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: Draw polygons in the coordinate plane given coordinates for the vertices; use coordinates to find the length of a side joining points with the same first coordinate or the same second coordinate. Apply these techniques in the context of solving real-world and mathematical problems.
problem_activity: Activity
The purpose of this task is for students to practice plotting coordinates in all four quadrants and find horizontal and vertical distances between coordinates in a puzzle. In past activities, students have been told the scale for the distance between grid lines, but here they must determine that each grid square has length 2 from the information given.
Digital
Launch
Arrange students in groups of 2. Tell students that they should not assume that each grid box is 1 unit. Give students 10 minutes quiet work time and 2 minutes for partner discussion. Follow with whole-class discussion.
Students using digital materials will be able to create a path through the maze by plotting points with an applet.
Representation: Internalize Comprehension.
Check in with students after the first 2–3 minutes of work time. Check to make sure students have selected appropriate coordinates for the first points of Andre’s route through the maze.
Supports accessibility for: Conceptual processing; Organization
Conversing: MLR5 Co-craft Questions.
Display only the picture of the maze and ask pairs of students to write possible mathematical questions about the situation. This is an opportunity for students to think about and relate to previous questions from previous lessons. Then, invite pairs to share their questions with the class. This helps students produce the language of mathematical questions and talk about the coordinate grid and the points on the maze.
Design Principle(s): Optimize output (for explanation); Maximize meta-awareness
Student Facing
The following diagram shows Andre’s route through a maze. He started from the lower right entrance.
[IMG]
What are the coordinates of the first two and the last two points of his route?
How far did he walk from his starting point to his ending point? Show how you know.
Jada went into the maze and stopped at
\((\text-7, 2)\)
.
Plot that point and other points that would lead her out of the maze (through the exit on the upper left side).
How far from
\((\text-7, 2)\)
must she walk to exit the maze? Show how you know.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Print
Launch
Arrange students in groups of 2. Tell students that they should not assume that each grid box is 1 unit. Give students 10 minutes quiet work time and 2 minutes for partner discussion. Follow with whole-class discussion.
Students using digital materials will be able to create a path through the maze by plotting points with an applet.
Representation: Internalize Comprehension.
Check in with students after the first 2–3 minutes of work time. Check to make sure students have selected appropriate coordinates for the first points of Andre’s route through the maze.
Supports accessibility for: Conceptual processing; Organization
Conversing: MLR5 Co-craft Questions.
Display only the picture of the maze and ask pairs of students to write possible mathematical questions about the situation. This is an opportunity for students to think about and relate to previous questions from previous lessons. Then, invite pairs to share their questions with the class. This helps students produce the language of mathematical questions and talk about the coordinate grid and the points on the maze.
Design Principle(s): Optimize output (for explanation); Maximize meta-awareness
Student Facing
The following diagram shows Andre’s route through a maze. He started from the lower right entrance.
[IMG]
What are the coordinates of the first two and the last two points of his route?
How far did he walk from his starting point to his ending point? Show how you know.
Jada went into the maze and stopped at
\((\text-7, 2)\)
.
Plot that point and other points that would lead her out of the maze (through the exit on the upper left side).
How far from
\((\text-7, 2)\)
must she walk to exit the maze? Show how you know.
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
The key idea is that it is possible to find distances and describe situations involving movement using the coordinate plane. This abstraction is important to appreciate because it means we can use numbers (in this case,
pairs
of numbers in the coordinate plane) to model situations that involve distance or movement. This will play a key role in later studies.To highlight these ideas, consider asking:
How were you or your partner able to find the coordinates in the maze? Did you come up with any strategies or shortcuts?
How did you find the distances that Andre and Jada traveled?
What other situations involving movement could be represented with a coordinate plane?
Students may come up with examples like board games, maps, and perhaps even 3-dimensional examples.


aligns: yes