few_shots: 
Example:
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_001392_neg_0

8
standard_description: Write simple expressions that record calculations with numbers, and interpret numerical expressions without evaluating them. For example, express the calculation “add 8 and 7, then multiply by 2” as 2 × (8 + 7). Recognize that 3 × (18932 + 921) is three times as large as 18932 + 921, without having to calculate the indicated sum or product.
problem_activity: Problem 1
a.   Kyle has 6 Skittles.
$${{1\over3}}$$
of them are red. How many of Kyle's Skittles are red?
b.   Samantha also has 6 Skittles.
$${{2\over3}}$$
of them are red. How many of Samantha’s Skittles are red?
Problem 2
a.   Find the value of each of the following.
|  i.                                 $$\frac{1}{3}$$                                of 9   | ii.                                 $$\frac{2}{3}$$                                of 9  |
|-------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------|
| iii.                                 $$\frac{1}{5}$$                                of 10 | iv.                                 $$\frac{4}{5}$$                                of 10 |
|  v.                                 $$\frac{1}{4}$$                                of 12  | vi.                                 $$\frac{2}{4}$$                                of 12 |
b.   What do you notice about the solutions to the computations in the leftmost column of the table? What do you wonder?
c.   What do you notice about the solutions in each row of the table? What do you wonder?
Problem 3
a.   Mrs. Pham has 8 apples. She wants to give
$${{3\over4}}$$
of the apples to her students. How many apples will her students get?
b.   In a class of 24 students,
$${{5\over6}}$$
of them are boys. How many boys are in the class?


aligns: no