few_shots: 
Example:
Problem/activity:
Problem 1
The table below contains single equations in a single variable, single equations in two variables, and pairs of simultaneous equations in two variables. Check the appropriate box to show whether there is no solution, exactly 1 solution, or if there is an infinite number of solutions.
|                                                          | **           No solution          ** | **           Exactly 1 solution          ** | **           Infinite number of solutions          ** |
|----------------------------------------------------------|--------------------------------------|---------------------------------------------|-------------------------------------------------------|
|                       $${9=4x+7}$$                       |                                      |                                             |                                                       |
|                       $${y=3y+5}$$                       |                                      |                                             |                                                       |
|                    $${y={x\over2}}$$                     |                                      |                                             |                                                       |
|                     $${3x+6y-9=0}$$                      |                                      |                                             |                                                       |
|    $${x=y}$$                        $${1.25x=1.25y}$$    |                                      |                                             |                                                       |
| $${9.9=6x+8y}$$                        $${9x=2.5y-8.8}$$ |                                      |                                             |                                                       |
| $${11x-2y=1.5}$$                        $${11x-2y=2.5}$$ |                                      |                                             |                                                       |
Problem 2
Kim has a small container and a large container as shown.
[IMG]
It takes 16 of the small containers to fill the large container. Three small containers leave 1.95 gallons of space in the big container.
What is the size of each of the two containers?


Concept/skill: 
Prove that, given a system of two equations in two variables, replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions.

Answer: 
No. Completing neither of these problems requires replacing one equation by the sum of that equation and a multiple of the other equation.

Now, does the problem or activity shown below enable students to learn the full intent of the following concept or skill?

shot_info: fl_problem_001392_neg_0

8
standard_description: Use a pair of perpendicular number lines, called axes, to define a coordinate system, with the intersection of the lines (the origin) arranged to coincide with the 0 on each line and a given point in the plane located by using an ordered pair of numbers, called its coordinates. Understand that the first number indicates how far to travel from the origin in the direction of one axis, and the second number indicates how far to travel in the direction of the second axis, with the convention that the names of the two axes and the coordinates correspond (e.g., x-axis and x-coordinate, y-axis and y-coordinate).
problem_activity: Narrative
The purpose of this activity is for students to use informal language and the structure of the coordinate grid to describe a given shape. Some questions may be about properties of the shape rather than its location. For example, “Is the rectangle wider than it is tall?” is a question that eliminates many shapes. As the number of shapes decreases, the location will become more important and the features of the coordinate grid will play a larger role. The synthesis gives students an opportunity to consider how the numbers in the coordinate grid can be useful to accurately describe the attributes, location, and orientation of a given shape (MP6).
Launch
Groups of 2
Activity
5 minutes: partner work time
Monitor for students who:
reference the structure of the grid in their questions
reference the numbers on the horizontal and vertical axes in their questions
use gestures to indicate horizontal or vertical gridlines
use the words horizontal or vertical
Student Facing
Play a round of Guess Which One.
Sit next to your partner.
Partner A:
Mentally choose a shape card without indicating which shape card you chose.
Partner B:
Ask yes or no questions to determine which shape card partner A has chosen.
A
[IMG]
B
[IMG]
C
[IMG]
D
[IMG]
E
[IMG]
F
[IMG]
G
[IMG]
H
[IMG]
I
[IMG]
J
[IMG]
K
[IMG]
L
[IMG]
Switch roles and play another round of Guess Which One.
Diego and Kiran were playing a round of Guess Which One. These are the last two shapes. What question can Kiran ask to determine which shape is the one that Diego picked?
[IMG]
[IMG]
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Advancing Student Thinking
If students do not reference the grid lines or numbers when asking questions, refer to the display from the first activity and ask, “Which words can you use to help you figure out which shape your partner chose?”
Activity Synthesis
Ask previously identified students to share their reasoning.
“How do the numbers help us locate shapes on the grid?” (I could use them to describe the lines and the points. I could also use numbers to describe the location of the shape: “Go up three. Go over 5.”)
“The gridlines with numbers on them are called
axes
. The coordinate grid has a
horizontal axis
and a
vertical axis
.”


aligns: yes