CPM Homework Help : ACC6 Problem 3-32

At Cassie’s Cashew Shoppe, a sign says, “Today only: $20\%$ off anything.” Maribel realizes that she has a coupon for $\frac { 1 } { 5 }$ off the price of anything in the shop. Which discount should she use, the $20\%$ -off deal or the $\frac { 1 } { 5 }$ -off coupon? Does it matter? Explain.

Hint:

$20\% \text{ is the same as }\frac{20}{100}.\text{ Can you use a percent ruler or number line to represent this?}$

Hint:

$\text{Using the same ruler or number line to represent }\frac{1}{5}\text{ and 20% might help you compare the portions.}$

$\text{Remember that one whole, or 100%, is the same as }\frac{5}{5}.$

Hint:

$\text{Your number line might resemble the one below. Can you place 20% and }\frac{1}{5}?$

A percent ruler is scaled by 25% and labeled 0%, 25%, 50%, 75%, and 100%. Above the 0% is 0. Above the 100% is 5.

More Help:

When you plot the portions, what do you find? Remember to explain your answer!