options: Apply properties of operations as strategies to add, subtract, factor, and expand linear expressions with rational coefficients.

Understand that rewriting an expression in different forms in a problem context can shed light on the problem and how the quantities in it are related. For example, a + 0.05a = 1.05a means that “increase by 5%” is the same as “multiply by 1.05.”
problem_activity: Problem 1
Read each situation below and then answer the questions that follow.
Situation A:
In the spring, an animal shelter had 216 animals. By the end of the summer, this number decreased by 8%. How many animals were at the shelter at the end of summer?
Situation B:
After advertising for adoptions on local television, an animal shelter decreased the number of animals at the shelter by 8%. There are now 216 animals. How many animals were at the shelter before the advertising?
a.   Sketch a visual diagram to represent each situation.
b.   How are the two situations similar?
c.   How are the two situations different?
Problem 2
A store sells backpacks in two sizes: small and large. The large backpacks sell for 20% more than the smaller backpacks. If a large backpack costs $75, how much does the small size cost?
Draw a visual representation of the situation, and then use an equation to solve.


correct_option_index: 1