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 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_pos_0

6

fl_problem_001097_pos_0

7

fl_problem_001392_neg_0

8
standard_description: Compose simple shapes to form larger shapes. For example, “Can you join these two triangles with full sides touching to make a rectangle?”
problem_activity: Narrative
The purpose of this activity is to build towers with solid shapes and count how many solid shapes are in the tower. Students will need to think strategically about which shapes to use and their properties. For stacking shapes, it is important to have flat faces. Students may notice that spheres can not be used to build towers. Pyramids and cones can be used as the top of the tower, but nothing can be stacked on top of them. The purpose of the activity synthesis is to discuss the attributes of shapes and why students chose the shapes they did to build their towers.
MLR8 Discussion Supports.
During group work, invite students to take turns sharing their responses. Ask students to restate what they heard using precise mathematical language and their own words. Original speakers can agree or clarify for their partner.
Advances: Listening, Speaking
Required Materials
Materials to Gather
Geoblocks
Solid shapes
Launch
Groups of 2
Give students access to solid shapes and geoblocks.
“Use solid shapes to make the tallest tower you can.”
3 minutes: independent work time
Activity
“Compare with your partner. How are your towers the same? How are they different?” (Sample response: We both used a lot of cubes. My tower has a point on top. My partner’s tower is taller.)
30 seconds: quiet think time
1 minute: partner discussion
Share responses.
“Write a number to show how many solid shapes you used in your tower.”
2 minutes: independent work time
“Did you or your partner use more solid shapes in their tower?”
30 seconds: quiet think time
1 minute: partner discussion
Share responses.
Student Facing
How many solid shapes did you use in your tower?
_______________
Activity Synthesis
Invite students to share their towers.
“What shapes did ____ use?” (There are some cubes and a pyramid on top.)
“How many shapes did ___ use?” (4)
“Did you use a sphere in your tower? Why?” (No. I could not put anything on top of it because it’s round. It rolled away because it’s round.)
“Did you use a cone in your tower?” (It worked at the very top but I could not put anything on top of the cone.)


aligns: yes