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: Recognize that a measure of center for a numerical data set summarizes all of its values with a single number, while a measure of variation describes how its values vary with a single number.
problem_activity: Problem 1
Act 1: Look at the following recipe -
[IMG]
What do you notice? What do you wonder?
Problem 2
Act 2: Use the following information to determine how many batches of cake can be made, how many servings can be made, and how much of each ingredient are needed to make that much cake -
This is how many eggs there are:
[IMG]
This is how much oil there is:
[IMG]
There are 4 boxes of cake mix.
Water will come from the tap.
Each box of cake makes 12 servings.
Problem 3
Act 3: Reveal the answer –
There is enough of each ingredient to make
$$2\frac{2}{3}$$
boxes, which would produce 32 servings of cake.
To make
$$2\frac23$$
boxes, you need
$$2\frac23$$
cups of water,
$$\frac89$$
cups of vegetable oil, and 8 eggs.
Was your answer reasonable? Why or why not?
Problem 4
Act 4 (the sequel):
Keaton wants to make enough cake so that every student in his fifth grade could have some. There are 100 students in fifth grade. How much more of each ingredient above would Keaton need?


aligns: no