few_shots: 
Example 1:
Concept/skill: 
Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.

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?


Answer: 
Yes. This problem solves a real-world problem involving mixing ingredients for cookies. A student doing this problem would need to reason about equivalent ratios of butter amounts to sugar amounts.

Example 2:
Concept/skill: 
Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.

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
$$-\frac{1}{4}$$


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

Example 3:
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.

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?


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, determine whether the following problem or activity can enable students to understand the concepts or skills in the provided description.

shot_info: fl_problem_000972_pos_0

6

fl_problem_001097_neg_0

7

fl_problem_001392_neg_0

8
standard_description: Understand the relationship between numbers and quantities; connect counting to cardinality.
problem_activity: Narrative
The purpose of this activity is for students to compare a Put Together, Total Unknown story problem and a Put Together/Take Apart, Both Addends Unknown story problem with a similar context. This is the first time that students have worked with a Put Together/Take Apart, Both Addends Unknown story problem.
Representation: Access for Perception.
Synthesis: Create a visual display to represent each story. For Mai, draw 7 circles and ask, “how many should I color in yellow?” and “how many should I color in red?” (5 yellow and 2 red). For Lin, draw 8 unshaded circles, and ask, “do we know which colors to use for Lin’s apples?” (no, we do not know how many of each color she picked).
Supports accessibility for: Visual-Spatial Processing, Organization
Launch
Groups of 2
Read both stories.
“What do you notice? What do you wonder?” (There are 2 stories. They are both about picking apples. There are red apples and yellow apples in both. I wonder how many red apples Lin picked.)
Activity
Read the first story problem.
“What do you know about Mai’s apples in this story? What do you not know?” (We know that she picked red and yellow apples. We know that she picked 5 yellow apples and 2 red apples. We do not know how many apples she picked altogether.)
30 seconds: quiet think time
1 minute: partner discussion
Share responses.
Read the second story problem.
“What do you know about Lin’s apples in this story? What do you not know?” (We know that she picked 8 apples. We know that some of them were red and some of them were yellow. We don’t know how many red ones or how many yellow ones she picked.)
30 seconds: quiet think time
1 minute: partner discussion
Share responses.
Student Facing
Mai was picking apples at the orchard.
Mai picked 5 yellow apples and 2 red apples.
Lin picked 8 apples at the orchard.
Some of the apples were yellow.
The rest of the apples were red.
[IMG]
[IMG]
Activity Synthesis
“What is the same about these stories?” (They are both about picking apples. They both have red and yellow apples.)
“What is different about the stories?” (The first story is about Mai and the next story is about Lin. In the first story we knew how many yellow apples and how many red apples. In the second story we know that there are 8 apples altogether.)
“In the next activity, we will work on showing what happened in the second story.”


aligns: no