Unit 1: Understanding and Representing Ratios

Lesson 1

Define ratio and use ratio language to describe associations between two or more quantities.

You have the following collection of shapes:

These shapes can be sorted into different groups. For example, you can make a group of squares and a group of circles. We can use ratios to describe how these groups are related; for example, the ratio of squares to circles is 4 to 10, or 4:10.

Sort the shapes into as many different groups as you can think of. For each one, describe the association between the groups using a ratio.

Some teachers and students are playing games during recess.

- 16 students play basketball
- 6 teachers play basketball
- 8 students jump rope
- 2 teachers jump rope

After recess, Mr. Hill shares this information with his class. He asks his students to compare the students and teachers playing different games.

Mika said: “Eight more students played basketball than jumped rope.”

Chaska said: “For every student who jumped rope, two students played basketball.”

Mr. Hill said, “Mika compared the students by looking at the difference, and Chaska compared the students using a ratio."

a. Compare the number of teachers who played basketball and jumped rope using the difference. Write your answer as a sentence as Mika did.

b. Compare the number of teachers who played basketball and jumped rope using a ratio. Write your answer as a sentence as Chaska did.

c. Compare the number of students who played basketball to the number of teachers who played basketball using a ratio. Write your answer in two different ways.

Abigail mixed 2 cups of white paint with 6 tablespoons (T) of blue paint.

Write at least four ratio statements to describe the situation. Can you write more than four?

Different types of sports balls are shown below.

Write 4 ratio statements to compare the different types of sports balls in the collection.