Lesson 11

Percentages and Double Number Lines

Let’s use double number lines to represent percentages.

Problem 1

Solve each problem. If you get stuck, consider using the double number lines.

  1. During a basketball practice, Mai attempted 40 free throws and was successful on 25% of them. How many successful free throws did she make?

    A double number line.
  2. Yesterday, Priya successfully made 12 free throws. Today, she made 150% as many. How many successful free throws did Priya make today?

    A double number line.

Problem 2

A 16-ounce bottle of orange juice says it contains 200 milligrams of vitamin C, which is 250% of the daily recommended allowance of vitamin C for adults. What is 100% of the daily recommended allowance of vitamin C for adults?

Double number line, 6 evenly spaced tick marks. Top line, vitamin C, milligrams. Beginning at first tick mark, labels: 0, blank, blank, blank, blank, blank. Bottom line, percent. Scale 0 to 250, by 50’s.


Problem 3

At a school, 40% of the sixth-grade students said that hip-hop is their favorite kind of music. If 100 sixth-grade students prefer hip hop music, how many sixth-grade students are at the school? Explain or show your reasoning.

Problem 4

Diego has a skateboard, scooter, bike, and go-cart. He wants to know which vehicle is the fastest. A friend records how far Diego travels on each vehicle in 5 seconds. For each vehicle, Diego travels as fast as he can along a straight, level path.

vehicle distance traveled
skateboard 90 feet
scooter 1,020 inches
bike 4,800 centimeters
go-cart 0.03 kilometers
  1. What is the distance each vehicle traveled in centimeters?

  2. Rank the vehicles in order from fastest to slowest.
(From Unit 3, Lesson 9.)

Problem 5

It takes 10 pounds of potatoes to make 15 pounds of mashed potatoes. At this rate:

  1. How many pounds of mashed potatoes can they make with 15 pounds of potatoes?
  2. How many pounds of potatoes are needed to make 50 pounds of mashed potatoes?
(From Unit 3, Lesson 7.)