few_shots: 
Example 1:
Concept/skill: 
Recognize and represent proportional relationships between quantities.

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: 
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:
Concept/skill: 
Apply and extend previous understandings of multiplication and division and of fractions to multiply and divide rational numbers.

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: 
Yes. This problem involves understanding fractions and division to divide rational numbers, such as 1, -4, 4, and -1. This problem also involves an understanding of multiplication: if p and q are integers, then -(p/q) = (-p)/q = p/(-q).

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_neg_0

6

fl_problem_001097_pos_0

7

fl_problem_001392_neg_0

8
standard_description: Apply and extend previous understandings of division to divide unit fractions by whole numbers and whole numbers by unit fractions. (Students able to multiply fractions in general can develop strategies to divide fractions in general, by reasoning about the relationship between multiplication and division. But division of a fraction by a fraction is not a requirement at this grade.)
problem_activity: Narrative
The purpose of this activity is for students to solve a contextual problem about dividing a fractional amount by a whole number. Students draw a diagram to represent the situation and relate the diagram to a division expression. Because of earlier work in this unit, students may draw one of the familiar square area diagrams showing the product
\(\frac{1}{3} \times \frac{1}{2}\)
. Other students may make a diagram resembling the macaroni and cheese pan and divide it appropriately. The focus in the synthesis is on bringing out how the diagram shows
\(\frac{1}{2} \div 3\)
and how it allows students to answer the question. The relationship between
\(\frac{1}{3} \times \frac{1}{2}\)
and
\(\frac{1}{2} \div 3\)
will be brought out in later lessons. When students connect the quantities in the story problem to an equation, they reason abstractly and quantitatively (MP2).
This activity uses
MLR7 Compare and Connect.
Advances: Representing, Conversing.
Representation: Develop Language and Symbols.
Represent the problem in multiple ways to support understanding of the situation. For example, a cut-out or another physical manipulative to represent the pan of macaroni and distribute the “macaroni” to three students or a video that shows the distribution of macaroni and cheese between three people.
Supports accessibility for: Attention, Conceptual Processing
Launch
Groups of 2
Display and read: “Last night, Jada’s aunt baked a pan of macaroni and cheese for dinner. Today, she brought the leftovers to Jada’s home for Jada and her sisters to share.”
“What do you notice? What do you wonder?” (We solved problems about macaroni and cheese before. I wonder how much macaroni and cheese Jada’s aunt brought.)
1–2 minutes: partner discussion
Activity
1–2 minutes: quiet think time
6–8 minutes: partner work time
Monitor for students who:
draw diagrams like the ones in the student responses
explain the situation as
\(\frac {1}{2}\)
divided into 3 equal pieces
recognize each person will get
\(\frac{1}{6}\)
of the whole pan of macaroni and cheese
Student Facing
Jada and her 2 sisters equally share
\(\frac{1}{2}\)
a pan of macaroni and cheese.
Draw a diagram to represent the situation.
Explain how this expression represents the situation:
\(\frac {1}{2} \div 3\)
How much of the whole pan of macaroni and cheese will each person get?
Student Response
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Activity Synthesis
MLR7 Compare and Connect
“Create a visual display that shows your thinking about the problems. You may want to include details such as notes, diagrams, drawings, etc., to help others understand your thinking.”
2–5 minutes: independent or group work
5–7 minutes: gallery walk
“How does each representation show
\(\frac {1}{2}\)
a pan of macaroni and cheese?”
“How does each representation show 3 equal pieces?”
30 seconds: quiet think time
1 minute: partner discussion
“How do we know that each person got the same amount of macaroni and cheese?” (I divided the half into 3 equal shares.)
“How much of the whole pan of macaroni and cheese did each person get?” (
\(\frac {1}{6}\)
)
“How do the diagrams show
\(\frac {1}{6}\)
?” (Each
\(\frac {1}{2}\)
of the pan is divided into 3 equal pieces, so each of those pieces is
\(\frac {1}{6}\)
of the whole pan.)


aligns: yes