Main Idea and Vocabulary

Key Concept: Ratios

Example 1:Write Ratios in Simplest Form

Example 2:Identify Equivalent Ratios

• Ratio – Comparison of two quantities by division

• equivalent ratios – Ratios that express the same relationships between two quantities

• Write ratios as fractions in simplest form and determine whether two ratios are equivalent (2.1.8D) (M7.A.2.2).

Write Ratios in Simplest Form

APPLES Mr. Gale bought a basket of apples. Using the table below, write a ratio comparing the Red Delicious to the Granny Smith apples as a fraction in simplest form.

Red DeliciousGranny Smith

Answer: The ratio of Red Delicious apples to Granny

Smith apples is

Mr. Gale’s Apples

12 Fuji 9 Granny Smith30 Red Delicious

1. A

2. B

3. C

4. D0% 0%0%0%

A.

B.

C.

D.

FLOWERS A garden has 18 roses and 24 tulips. Write a ratio comparing roses to tulips as a fraction in simplest form.

Identify Equivalent Ratios

Determine whether the ratios 12 onions to 15 potatoes and 32 onions to 40 potatoes are equivalent.

Write each ratio as a fraction in simplest form.

Answer:

So, 12:15 and 32:40 are equivalent ratios.

The GCF of 12 and 15 is 3.

The GCF of 32 and 40 is 8.

1. A

2. B

A. yes

B. no

Determine whether the ratios 3 cups vinegar to 8 cups water and 5 cups vinegar to 12 cups of water are equivalent.

0%0%

REVIEW

Use the information in the table to write

each ratio as a fraction in simplest form.

1. Adults: students

2. Students: buses

3. Buses: people

4. Adults: people

Field Trip Statistics

Students 180

Adults 24

Buses 4

15

2

1

45

51

1

17

2

REVIEW

Determine whether the ratios are equivalent. Explain.

5. 12 out of 20 doctors agree; 6 out of 10 doctors agree

6. 2 DVDs to 7 CDs; 10 DVDs to 15 CDs

5

3

10

6

5

3

20

12; andyes

3

2

15

10

7

2; orno

End of the Lesson

Five-Minute Check (over Chapter 5)

Image Bank

Math Tools

Scale Drawings

Using Proportions