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: Solve real-world and mathematical problems involving the four operations with rational numbers. (Computations with rational numbers extend the rules for manipulating fractions to complex fractions.)
problem_activity: Problem 1
In a 30-minute television show, 12 minutes of the airtime are spent on commercials.
a.   Draw a visual representation of the problem.
b.   Determine what percent of the television show’s airtime is spent on commercials. Choose any strategy.
c.   Find a peer who used a different strategy to solve than you did. Compare and discuss your strategies and solutions.
Problem 2
Cole and Jamie are raising money for the annual Walk for Hunger in their city. They each have a goal to raise $250. So far, Cole has raised $150 and Jamie has raised $180.
a.   What percent of their goal did each boy raise so far?
b.   What is the amount that Cole raised as a percent of the amount Jamie raised?
c.   What is the amount Jamie raised as a percent of the amount Cole raised?
Problem 3
At a middle school, 480 students in sixth through eighth grade responded to a survey that asked them what their favorite season was. The circle graph below shows some of the data from the survey.
Student Survey “Favorite Season”
[IMG]
a.   How many students chose spring as their favorite season?
b.   What percent of students chose summer as their favorite season?
c.   In just the sixth-grade class, 28 students chose winter as their favorite season. This was 20% of the sixth grade. How many students are in the sixth grade at this school?


aligns: yes