Lesson 14

Solving Percentage Problems

Let’s solve more percentage problems.

Problem 1

For each problem, explain or show your reasoning.

  1. 160 is what percentage of 40?
  2. 40 is 160% of what number?
  3. What number is 40% of 160?

Problem 2

A store is having a 20%-off sale on all merchandise. If Mai buys one item and saves $13, what was the original price of her purchase? Explain or show your reasoning.

Problem 3

The original price of a scarf was $16. During a store-closing sale, a shopper saved $12 on the scarf. What percentage discount did she receive? Explain or show your reasoning.

Problem 4

Select all the expressions whose value is larger than 100.

A:

120% of 100

B:

50% of 150

C:

150% of 50

D:

20% of 800

E:

200% of 30

F:

500% of 400

G:

1% of 1,000

Problem 5

An ant travels at a constant rate of 30 cm every 2 minutes.

  1. At what pace does the ant travel per centimeter?
  2. At what speed does the ant travel per minute?
(From Unit 3, Lesson 8.)

Problem 6

Is 3\(\frac{1}{2}\) cups more or less than 1 liter? Explain or show your reasoning. (Note: 1 cup \(\approx\) 236.6 milliliters)

(From Unit 3, Lesson 4.)

Problem 7

Name a unit of measurement that is about the same size as each object.

  1. The distance of a doorknob from the floor is about 1 _____________.

  2. The thickness of a fingernail is about 1 _____________.

  3. The volume of a drop of honey is about 1 _____________.

  4. The weight or mass of a pineapple is about 1 _____________.

  5. The thickness of a picture book is about 1 _____________.

  6. The weight or mass of a buffalo is about 1 _____________.

  7. The volume of a flower vase is about 1 _____________.

  8. The weight or mass of 20 staples is about 1 _____________.

  9. The volume of a melon is about 1 _____________.

  10. The length of a piece of printer paper is about 1 _____________.

(From Unit 3, Lesson 2.)