few_shots: 
Example 1:
Problem/activity:
You’re mixing ingredients for cookies. The recipe says to combine 6 tablespoons, or ¾ stick, of butter with 1 cup of sugar. You accidentally mix in a whole stick of butter (8 tablespoons) with the cup of sugar. How can you fix this?


Concept/skill: 
Recognize and represent proportional relationships between quantities.

Answer: 
No. Usually problems that teach recognizing and representing proportional relationships between quantities involve deciding whether two quantities are in a proportional relationship or identifying the constant of proportionality, and then representing proportional relationships by equations or explaining proportional relationship using coordinate graphs.

Example 2:
Problem/activity:
For each pair of numbers, determine if the values are equivalent. Explain your reasoning for each one.
a.
$$-0.25$$
and
$$\frac{1}{-4}$$
b.
$$-\left ( \frac{1}{4} \right )$$
and
$$\frac{-1}{-4}$$
c.
$$\frac{-1}{4}$$
and
$$-\frac{1}{4}$$


Concept/skill: 
Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.

Answer: 
No. The expressions shown in this problem do not involve multiplying fractions with other fractions, nor whole numbers with fractions.

Example 3:
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: 
Analyze and solve pairs of simultaneous linear equations.

Answer: 
Yes. The last three rows of the table in the first problem involves solving pairs of simultaneous linear equations. The second word problem can also be represented as two simultaneous linear equations.

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_000972_neg_0

6

fl_problem_001097_neg_0

7

fl_problem_001392_pos_0

8
standard_description: Understand the concept of a unit rate a/b associated with a ratio a:b with b ≠0, and use rate language in the context of a ratio relationship. For example, “This recipe has a ratio of 3 cups of flour to 4 cups of sugar, so there is 3/4 cup of flour for each cup of sugar.” “We paid $75 for 15 hamburgers, which is a rate of $5 per hamburger.” (Expectations for unit rates in this grade are limited to non-complex fractions.)
problem_activity: Problem 1
A repair technician replaces cracked screens on phones. He can replace 5 screens in 3 hours.
a.   Write an equation you can use to determine how long it takes to replace any number of screens.
b.   Write an equation you can use to determine how many screens can be replaced in a certain number of hours.
c.   Use one of your equations to determine how long it would take to replace 30 screens.
d.   Use one of your equations to determine how many screens could be replaced in 12 hours.
Problem 2
A train traveling from Boston to New York moves at a constant speed. The train covers 260 miles in 3.25 hours.
Write an equation that represents this relationship. Explain what your equation tells you about the train.
Problem 3
Deli turkey meat is on sale at two different grocery stores, as represented below.
| **             Stop & Buy            **              $$c=6.25p$$                        , where                         $$c$$                        represents cost in dollars and                         $$p$$                        represents number of pounds of turkey |                        **             Roger's            **                         | **                 Amount                **  **                 (pounds)                ** | **                 Cost                **  **                 ($)                ** | 3 | 19.50 | 4 | 26.00 | 6 | 39.00 | 7 | 45.50 |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------|---|-------|---|-------|---|-------|---|-------|
|                                                                                           **                 Amount                **  **                 (pounds)                **                                                                                           | **                 Cost                **  **                 ($)                ** |                                                                                            |                                                                                     |   |       |   |       |   |       |   |       |
|                                                                                                                                       3                                                                                                                                        |                                        19.50                                        |                                                                                            |                                                                                     |   |       |   |       |   |       |   |       |
|                                                                                                                                       4                                                                                                                                        |                                        26.00                                        |                                                                                            |                                                                                     |   |       |   |       |   |       |   |       |
|                                                                                                                                       6                                                                                                                                        |                                        39.00                                        |                                                                                            |                                                                                     |   |       |   |       |   |       |   |       |
|                                                                                                                                       7                                                                                                                                        |                                        45.50                                        |                                                                                            |                                                                                     |   |       |   |       |   |       |   |       |
What is the unit price of turkey per pound at each store? Which store has the better sale?


aligns: no