+----------------------+-----------------------------------------------+
| Drive A Car\         |                                               |
| The first Squeak     |                                               |
| Etoys project for    |                                               |
| children.\           |                                               |
| How they design,     |                                               |
| build, get to turn,  |                                               |
| and learn to drive   |                                               |
| their car.           |                                               |
|                      |                                               |
| Written by Alan Kay  |                                               |
| and updated slightly |                                               |
| by Randall Caton on  |                                               |
| May 2006.            |                                               |
+----------------------+-----------------------------------------------+
| A favorite first     |                                               |
| Squeak Etoys project |                                               |
| for 9, 10 and 11     |                                               |
| year olds is to      |                                               |
| design a car they    |                                               |
| would like to learn  |                                               |
| to drive, make the   |                                               |
| car with computer    |                                               |
| stuff, and play with |                                               |
| it by themselves and |                                               |
| with others. Then    |                                               |
| they can make it     |                                               |
| into a robot car,    |                                               |
| race it, and then    |                                               |
| learn how to make    |                                               |
| fun animations.      |                                               |
+----------------------+-----------------------------------------------+
| ***This project      |                                               |
| introduces them to   |                                               |
| many of the Etoy     |                                               |
| materials and tools  |                                               |
| (and it is also a    |                                               |
| good way to explain  |                                               |
| how Squeaking works  |                                               |
| to adults).***       |                                               |
+----------------------+-----------------------------------------------+
| The Squeak Etoys     | ![](                                          |
| desktop is mostly    | media/image1.png){width="4.166666666666667in" |
| bare to make the     | height="2.9375in"}                            |
| most room for the    |                                               |
| children\'s work and |                                               |
| play. There are      |                                               |
| popout flaps that    |                                               |
| hold supplies,       |                                               |
| suggestions and      |                                               |
| help, links to       |                                               |
| mentors, navigation  |                                               |
| aids to find and     |                                               |
| save projects and    |                                               |
| provide access to    |                                               |
| tools such as the    |                                               |
| painting kit.        |                                               |
+----------------------+-----------------------------------------------+
| The paint kit        | ![](m                                         |
|                      | edia/image2.png){width="1.0833333333333333in" |
|                      | height="3.3645833333333335in"}                |
+----------------------+-----------------------------------------------+
|                      |                                               |
|                      |                                               |
| There are 5 parts in |                                               |
| this description of  |                                               |
| the project:         |                                               |
|                      |                                               |
| o I. Paint the car\  |                                               |
| o II. Make A Simple  |                                               |
| Script\              |                                               |
| o III. Steer The Car |                                               |
| Using The Script\    |                                               |
| o IV. Make a         |                                               |
| Steering Wheel and   |                                               |
| Attach It To The     |                                               |
| Car\                 |                                               |
| o V. Get Advice      |                                               |
| About How To Make    |                                               |
| Car More             |                                               |
| Controllable         |                                               |
+----------------------+-----------------------------------------------+

+----------------------+-----------------------------------------------+
| I. Paint The Car     |                                               |
+----------------------+-----------------------------------------------+
| The children start   | ![](                                          |
| by thinking about    | media/image3.png){width="4.166666666666667in" |
| what their car       | height="3.125in"}                             |
| should look like and |                                               |
| then paint it as     |                                               |
| seen from the top    |                                               |
| (this is a nice      |                                               |
| project for this age |                                               |
| in itself).          |                                               |
+----------------------+-----------------------------------------------+
| They press Keep when | ![](                                          |
| they are finished    | media/image4.png){width="4.166666666666667in" |
| with the painting.   | height="3.125in"}                             |
+----------------------+-----------------------------------------------+
| If the pointer       | ![](                                          |
| hovers over their    | media/image5.png){width="4.166666666666667in" |
| object, a \"halo of  | height="3.125in"}                             |
| handles\" with       |                                               |
| useful controls      |                                               |
| appears.             |                                               |
+----------------------+-----------------------------------------------+
| Their painting is a  | ![](                                          |
| graphic object and   | media/image6.png){width="4.166666666666667in" |
| can be resized       | height="3.125in"}                             |
| (using the yellow    |                                               |
| handle) rotated      |                                               |
| (using the blue      |                                               |
| handle), and         |                                               |
| repainted (using the |                                               |
| grey handle).        |                                               |
+----------------------+-----------------------------------------------+
| Then they \"open     | ![](                                          |
| up\" the car to      | media/image7.png){width="4.166666666666667in" |
| \"see\" its          | height="3.125in"}                             |
| properties with the  |                                               |
| light-blue handle.   |                                               |
+----------------------+-----------------------------------------------+
| For children of this |                                               |
| age, the textual     |                                               |
| form of these        |                                               |
| properties doesn\'t  |                                               |
| look as exciting as  |                                               |
| the iconic car that  |                                               |
| can be directly      |                                               |
| manipulated.         |                                               |
+----------------------+-----------------------------------------------+
| ***The \"Montessori  |                                               |
| game\" here is for   |                                               |
| the children to get  |                                               |
| most of their        |                                               |
| pay-off playing in   |                                               |
| the hand-eye arena,  |                                               |
| while gradually and  |                                               |
| subliminally gaining |                                               |
| fluency and          |                                               |
| appreciation of the  |                                               |
| power of symbols.*** |                                               |
+----------------------+-----------------------------------------------+
| But, the symbols can | ![](                                          |
| make the car do      | media/image8.png){width="4.166666666666667in" |
| things! For example, | height="3.125in"}                             |
| they can find the    |                                               |
| property called      |                                               |
| \"heading\" and      |                                               |
| click on the         |                                               |
| up-caret to make the |                                               |
| number bigger, and   |                                               |
| the car will turn in |                                               |
| response.            |                                               |
+----------------------+-----------------------------------------------+
| If they turn the car | ![](                                          |
| by hand using the    | media/image9.png){width="4.166666666666667in" |
| blue handle, the     | height="3.125in"}                             |
| value of the heading |                                               |
| property will        |                                               |
| change.              |                                               |
+----------------------+-----------------------------------------------+
| The visual image of  | ![](m                                         |
| the car pointing in  | edia/image10.png){width="4.166666666666667in" |
| a particular         | height="3.125in"}                             |
| direction and the    |                                               |
| property called      |                                               |
| heading are two      |                                               |
| different views of   |                                               |
| the same idea. The   |                                               |
| visual image of the  |                                               |
| whole car and the    |                                               |
| viewer of the car    |                                               |
| are two different    |                                               |
| views of the idea    |                                               |
| called \"car\".      |                                               |
|                      |                                               |
| The \"two different  |                                               |
| views of the same    |                                               |
| thing\" idea is made |                                               |
| clearer by giving    |                                               |
| the car a name such  |                                               |
| as \"red car\".      |                                               |
+----------------------+-----------------------------------------------+
| Some of the          | ![](m                                         |
| properties are       | edia/image11.png){width="4.166666666666667in" |
| behaviors. For       | height="3.125in"}                             |
| example, there is a  |                                               |
| behavior called      |                                               |
| \"forward by\". If   |                                               |
| the exclamation      |                                               |
| point is clicked on, |                                               |
| the behavior will be |                                               |
| triggered, and the   |                                               |
| car will move        |                                               |
| forward by the       |                                               |
| distance given in    |                                               |
| the number.          |                                               |
+----------------------+-----------------------------------------------+
| There is another     | ![](m                                         |
| behavior called      | edia/image12.png){width="4.166666666666667in" |
| \"turn by\".         | height="3.125in"}                             |
| Triggering this will |                                               |
| turn the car by this |                                               |
| number of degrees.   |                                               |
+----------------------+-----------------------------------------------+

+----------------------+-----------------------------------------------+
| II\. Make A Simple   |                                               |
| Script               |                                               |
+----------------------+-----------------------------------------------+
| Behaviors can be     | ![](m                                         |
| made into a script   | edia/image13.png){width="4.166666666666667in" |
| by dragging them out | height="3.125in"}                             |
| and dropping them on |                                               |
| the desktop. Let\'s  |                                               |
| drag out a \"forward |                                               |
| by\" tile and a      |                                               |
| \"turn by\" tile.    |                                               |
+----------------------+-----------------------------------------------+
| The script can be    | ![](m                                         |
| triggered to run     | edia/image14.png){width="4.166666666666667in" |
| over and over by     | height="3.125in"}                             |
| clicking on its      |                                               |
| clock.               |                                               |
+----------------------+-----------------------------------------------+
| We see that doing    | ![](m                                         |
| car forward by 5 and | edia/image15.png){width="4.166666666666667in" |
| car turn by 5 over   | height="3.125in"}                             |
| and over seems to    |                                               |
| move the car in a    |                                               |
| somewhat circular    |                                               |
| motion.              |                                               |
+----------------------+-----------------------------------------------+
| We can find out      | ![](m                                         |
| exactly what the car | edia/image16.png){width="4.166666666666667in" |
| is doing by dropping | height="3.125in"}                             |
| its pen - which will |                                               |
| trace its path : by  |                                               |
| going to the pen     |                                               |
| category in the      |                                               |
| viewer               |                                               |
+----------------------+-----------------------------------------------+
| and setting the      | ![](m                                         |
| property \"pen       | edia/image17.png){width="4.166666666666667in" |
| down\" to \"true\".  | height="3.125in"}                             |
|                      |                                               |
| In fact the car      |                                               |
| seems to draw a      |                                               |
| perfect circle.      |                                               |
+----------------------+-----------------------------------------------+

+------------------+---------------------------------------------------+
| III\. Steer The  |                                                   |
| Car Using The    |                                                   |
| Script           |                                                   |
+------------------+---------------------------------------------------+
| If we change     | !                                                 |
| either or both   | [](media/image18.png){width="4.166666666666667in" |
| of the numbers   | height="3.125in"}                                 |
| in the script,   |                                                   |
| the car will     |                                                   |
| still draw       |                                                   |
| circles, but of  |                                                   |
| different sizes. |                                                   |
+------------------+---------------------------------------------------+
| ***Clearly,      |                                                   |
| something        |                                                   |
| interesting has  |                                                   |
| been captured    |                                                   |
| here by these 10 |                                                   |
| year olds. Going |                                                   |
| a little and     |                                                   |
| turning a little |                                                   |
| over and over    |                                                   |
| seems to make    |                                                   |
| circles. Adults  |                                                   |
| may remember     |                                                   |
| something        |                                                   |
| complicated      |                                                   |
| about x2 + y2 =  |                                                   |
| r2 and wonder    |                                                   |
| why this way is  |                                                   |
| so simple. It\'s |                                                   |
| because when     |                                                   |
| looked at from   |                                                   |
| the view of an   |                                                   |
| ant on the rim   |                                                   |
| of a circle, a   |                                                   |
| circle is just a |                                                   |
| track of         |                                                   |
| constant         |                                                   |
| curvature. All   |                                                   |
| the ant has to   |                                                   |
| do is keep       |                                                   |
| itself moving    |                                                   |
| and turning      |                                                   |
| going at the     |                                                   |
| same rate to     |                                                   |
| trace out a      |                                                   |
| perfect          |                                                   |
| circle.***       |                                                   |
|                  |                                                   |
| ***This way of   |                                                   |
| looking at       |                                                   |
| geometry is      |                                                   |
| called \"the     |                                                   |
| differential     |                                                   |
| geometry of      |                                                   |
| vectors\" and is |                                                   |
| the main         |                                                   |
| mathematics used |                                                   |
| by science. It   |                                                   |
| is used by       |                                                   |
| scientists       |                                                   |
| because it is    |                                                   |
| simpler and more |                                                   |
| powerful than    |                                                   |
| the general math |                                                   |
| taught in K-12.  |                                                   |
| It is worth      |                                                   |
| pondering this   |                                                   |
| paradoxical      |                                                   |
| irony.***        |                                                   |
|                  |                                                   |
| ***But the       |                                                   |
| children are     |                                                   |
| only             |                                                   |
| peripherally     |                                                   |
| interested in    |                                                   |
| circles at this  |                                                   |
| point. They want |                                                   |
| to get on with   |                                                   |
| making their car |                                                   |
| so it can be     |                                                   |
| driven.***       |                                                   |
|                  |                                                   |
| ***This is a     |                                                   |
| really important |                                                   |
| point. \"The     |                                                   |
| play\'s the      |                                                   |
| thing\" here. It |                                                   |
| is our job to    |                                                   |
| make lots of     |                                                   |
| little aha\'s    |                                                   |
| happen during    |                                                   |
| the play, not to |                                                   |
| disrupt the      |                                                   |
| play. We are not |                                                   |
| trying to teach  |                                                   |
| them specific    |                                                   |
| math at this     |                                                   |
| point, but how   |                                                   |
| to be real       |                                                   |
| mathematicians.  |                                                   |
| The children     |                                                   |
| have to play     |                                                   |
| with math to do  |                                                   |
| this.***         |                                                   |
+------------------+---------------------------------------------------+
| First, they find | !                                                 |
| that they can    | [](media/image19.png){width="4.166666666666667in" |
| steer their car  | height="3.125in"}                                 |
| by changing the  |                                                   |
| number after     |                                                   |
| \"turn by\".     |                                                   |
+------------------+---------------------------------------------------+
| The bigger the   |                                                   |
| number the       |                                                   |
| larger the rate  |                                                   |
| of turn. Zero    |                                                   |
| goes straight.   |                                                   |
| Positive goes    |                                                   |
| right, negative  |                                                   |
| goes left. But   |                                                   |
| this is weak     |                                                   |
| tea. Real cars   |                                                   |
| are steered with |                                                   |
| a steering       |                                                   |
| wheel.           |                                                   |
+------------------+---------------------------------------------------+

  ---------------------- ----------------------------------------------------
  IV\. Make a Steering   
  Wheel and Attach It To 
  The Car                

  They paint a steering  ![](media/image20.png){width="4.166666666666667in"
  wheel.                 height="3.125in"}

  This is the same kind  ![](media/image21.png){width="4.166666666666667in"
  of object as the car,  height="3.125in"}
  but it has a different 
  costume. They name it  
  \"steer\" and recall   
  that it also has a     
  heading. They try      
  turning the steering   
  wheel and notice that  
  the property           
  \"steer\'s heading\"   
  gets larger and        
  smaller, goes          
  negative, etc.         

  Then they are shown    ![](media/image22.png){width="4.166666666666667in"
  that they can pick up  height="3.125in"}
  the name \"steer\'s    
  heading\" of the       
  direction numbers that 
  are being put out by   
  the steering wheel and 
  drop it over the       
  number where \"turn    
  by\" gets its input.   
  All of a sudden the    
  heading of the         
  steering wheel is now  
  controlling the car!   

  ***There is a huge     
  visceral flash at this 
  moment: the name       
  stands for the number! 
  This is a wonderful    
  way for these 10 year  
  olds to learn about    
  variables \-- a        
  subject about which    
  many adults retain     
  confusion \-- in a     
  painless and powerful  
  setting. Most children 
  do this learning from  
  a single exposure to   
  this example.***       

  The car is a bit       
  difficult to control   
  because the numbers    
  from the steering      
  wheel are too large    
  and the car            
  oversteers. The        
  children will ask how  
  to make it better. In  
  the classroom this is  
  an opportunity to show 
  them something neat.   
  But what if they are   
  at home doing this by  
  themselves or they     
  have a teacher who is  
  not confident about    
  this kind of           
  mathematics?           
  ---------------------- ----------------------------------------------------

+-----------------+----------------------------------------------------+
| V. Get Advice   |                                                    |
| About How To    |                                                    |
| Make Car More   |                                                    |
| Controllable    |                                                    |
+-----------------+----------------------------------------------------+
| The children    |                                                    |
| are connected   |                                                    |
| to the          |                                                    |
| Internet, and   |                                                    |
| part of the     |                                                    |
| Squeak system   |                                                    |
| is a registry   |                                                    |
| where children  |                                                    |
| who have        |                                                    |
| already done    |                                                    |
| projects can    |                                                    |
| sign up to be   |                                                    |
| mentors and     |                                                    |
| colleagues.     |                                                    |
| Colleagues are  |                                                    |
| represented by  |                                                    |
| badges with     |                                                    |
| their name and  |                                                    |
| picture on it.  |                                                    |
|                 |                                                    |
| Our child,      |                                                    |
| Beth, finds in  |                                                    |
| the \"folder of |                                                    |
| friends\" that  |                                                    |
| Yasie, who      |                                                    |
| lives in Kyoto, |                                                    |
| did this        |                                                    |
| project the     |                                                    |
| previous year.  |                                                    |
+-----------------+----------------------------------------------------+
| Her badge has a | ![](media/image23.png){width="4.166666666666667in" |
| glowing halo    | height="3.125in"}                                  |
| indicating that |                                                    |
| she is online,  |                                                    |
| so Beth         |                                                    |
| contacts her by |                                                    |
| pushing on the  |                                                    |
| chat button. To |                                                    |
| get the badge   |                                                    |
| drag an Object  |                                                    |
| Catalog out of  |                                                    |
| the Supplies    |                                                    |
| flap, click on  |                                                    |
| Collaborative,  |                                                    |
| and pull the    |                                                    |
| Badge onto the  |                                                    |
| workspace. You  |                                                    |
| also need to    |                                                    |
| drag out a      |                                                    |
| Listener, which |                                                    |
| you activate by |                                                    |
| clicking on the |                                                    |
| black           |                                                    |
| semicircle.     |                                                    |
+-----------------+----------------------------------------------------+
| Both text and   | !                                                  |
| voice chat are  | [](media/image24.png){width="4.3381944444444445in" |
| provided. They  | height="2.8020833333333335in"}                     |
| get acquainted  |                                                    |
| and finally     |                                                    |
| Beth asks how   |                                                    |
| she can control |                                                    |
| her car better. |                                                    |
| Yasie says      |                                                    |
| \"let me see    |                                                    |
| your screen\",  |                                                    |
| so Beth pushes  |                                                    |
| the Share       |                                                    |
| button, which   |                                                    |
| is dragged out  |                                                    |
| from the Object |                                                    |
| Catalog.        |                                                    |
+-----------------+----------------------------------------------------+
| Now Yasie gets  |                                                    |
| a window on     |                                                    |
| Beth\'s world   |                                                    |
| and can         |                                                    |
| interact with   |                                                    |
| her.            |                                                    |
+-----------------+----------------------------------------------------+
| Their pictures  | ![](media/image25.png){width="4.166666666666667in" |
| and names now   | height="3.125in"}                                  |
| show up on      |                                                    |
| their cursors.  |                                                    |
| Yassie shows    |                                                    |
| Beth that she   |                                                    |
| can do some     |                                                    |
| arithmetic on   |                                                    |
| the number      |                                                    |
| coming out of   |                                                    |
| the steering    |                                                    |
| wheel if she    |                                                    |
| clicks on the   |                                                    |
| little          |                                                    |
| triangle.       |                                                    |
+-----------------+----------------------------------------------------+
| This pops out   | ![](media/image26.png){width="4.166666666666667in" |
| an example      | height="3.125in"}                                  |
| expression. A   |                                                    |
| click on the    |                                                    |
| \"+\" shows     |                                                    |
| other possible  |                                                    |
| operators.      |                                                    |
+-----------------+----------------------------------------------------+
| Yasie explains  | ![](media/image27.png){width="4.166666666666667in" |
| that \"/\"      | height="3.125in"}                                  |
| (division) will |                                                    |
| work nicely     |                                                    |
| here: \"try     |                                                    |
| dividing by     |                                                    |
| 3\".            |                                                    |
+-----------------+----------------------------------------------------+
| The number      | ![](media/image28.png){width="4.166666666666667in" |
| after the \"/\" | height="3.125in"}                                  |
| is clicked up   |                                                    |
| to \"3\".       |                                                    |
+-----------------+----------------------------------------------------+
| Now Beth tries  | ![](media/image29.png){width="4.166666666666667in" |
| her steering    | height="3.125in"}                                  |
| wheel again and |                                                    |
| finds that the  |                                                    |
| car is much     |                                                    |
| more            |                                                    |
| controllable.   |                                                    |
+-----------------+----------------------------------------------------+
| ***For the      |                                                    |
| first time in   |                                                    |
| her 10 years on |                                                    |
| earth, she has  |                                                    |
| just learned    |                                                    |
| what division   |                                                    |
| is good for!*** |                                                    |
|                 |                                                    |
| **              |                                                    |
| *Multiplication |                                                    |
| and division    |                                                    |
| have no         |                                                    |
| importance in   |                                                    |
| most            |                                                    |
| children\'s     |                                                    |
| lives. They     |                                                    |
| don\'t need     |                                                    |
| them to divide  |                                                    |
| up M&Ms or      |                                                    |
| pizza.          |                                                    |
| Multiplication  |                                                    |
| and division    |                                                    |
| are used for    |                                                    |
| scaling things, |                                                    |
| but children    |                                                    |
| have very       |                                                    |
| little (usually |                                                    |
| nothing) that   |                                                    |
| needs scaling.  |                                                    |
| Here they do.   |                                                    |
| There is a      |                                                    |
| direct relation |                                                    |
| between         |                                                    |
| mathematics and |                                                    |
| the play the    |                                                    |
| children want   |                                                    |
| to do.***       |                                                    |
+-----------------+----------------------------------------------------+
| Now that Beth   |                                                    |
| has a nicely    |                                                    |
| working car,    |                                                    |
| she and Yasie   |                                                    |
| decide to play  |                                                    |
| a car game.     |                                                    |
| Yasie takes the |                                                    |
| car she made    |                                                    |
| and drops it    |                                                    |
| and its         |                                                    |
| steering wheel  |                                                    |
| onto the shared |                                                    |
| world           |                                                    |
+-----------------+----------------------------------------------------+
| and it is       | ![](media/image30.png){width="4.166666666666667in" |
| instantly       | height="2.9375in"}                                 |
| transmitted to  |                                                    |
| Beth and drops  |                                                    |
| on her desktop. |                                                    |
+-----------------+----------------------------------------------------+
| Yasie tells the |                                                    |
| shared window   |                                                    |
| to go to full   |                                                    |
| screen so she   |                                                    |
| has just what   |                                                    |
| Beth has on her |                                                    |
| screen.         |                                                    |
+-----------------+----------------------------------------------------+
| Now they get    | ![](media/image31.png){width="4.166666666666667in" |
| started on some | height="2.9375in"}                                 |
| serious play.   |                                                    |
| How about a     |                                                    |
| game called     |                                                    |
| \"Chase\"?      |                                                    |
+-----------------+----------------------------------------------------+
| Even better,    | !                                                  |
| how could a car | [](media/image32.jpeg){width="4.538888888888889in" |
| be made to act  | height="3.408333333333333in"}                      |
| like a          |                                                    |
| spaceship?      |                                                    |
+-----------------+----------------------------------------------------+
| ***\            |                                                    |
| 30 years ago    |                                                    |
| this was a      |                                                    |
| fantasy about   |                                                    |
| how children    |                                                    |
| would learn     |                                                    |
| science and     |                                                    |
| math some day   |                                                    |
| on their own    |                                                    |
| notebook        |                                                    |
| personal        |                                                    |
| \"Dynabooks\".  |                                                    |
| After many      |                                                    |
| years of        |                                                    |
| building and    |                                                    |
| testing these   |                                                    |
| ideas, today    |                                                    |
| this scenario   |                                                    |
| is real. For    |                                                    |
| the last        |                                                    |
| several years   |                                                    |
| hundreds of     |                                                    |
| children have   |                                                    |
| been building   |                                                    |
| their own       |                                                    |
| \"kinetic       |                                                    |
| art-math\" just |                                                    |
| like Beth and   |                                                    |
| Yasie in this   |                                                    |
| dynamic media   |                                                    |
| personal        |                                                    |
| computing       |                                                    |
| system.\        |                                                    |
| We have just    |                                                    |
| finished the    |                                                    |
| first complete  |                                                    |
| project for     |                                                    |
| most children.  |                                                    |
| To the child    |                                                    |
| the result is a |                                                    |
| working toy     |                                                    |
| made from       |                                                    |
| working toys.   |                                                    |
| To those who    |                                                    |
| are             |                                                    |
| mathematically  |                                                    |
| savvy, the      |                                                    |
| children have   |                                                    |
| started to      |                                                    |
| learn about     |                                                    |
| variables,      |                                                    |
| processes, and  |                                                    |
| differential    |                                                    |
| models in a     |                                                    |
| very deep       |                                                    |
| way.***         |                                                    |
+-----------------+----------------------------------------------------+