Page 171 - NUMINO TG_6A

11Unit Three Apples, Five Oranges

jOb ective Learn about ratios.

1. Textbook Instructions 11 Three Apples, Five Oranges

Have students compare the number of apples There are three apples and five oranges. Compare the number of apples
to oranges. to the number of oranges.
How many apples are there? 3 apples.
How many oranges are there? 5 oranges.

Ways to write a ratio:

Use words: a to b

Use a colon: a : b

As a fraction: b
a

An alternate method of setting up a ratio is 3 to 5, 3 3 5
5
to write an equation relating the two ,
quantities.
Apples

Oranges You can compare numbers by using ratios. A ratio is a comparison of

two numbers, a and b, and can be written as a fraction a .
b

Use words: 7 to 2 For example, you can use a ratio to compare the number of apples to

the number of oranges. This ratio can be written in three ways.

Use a colon: 7 : 2

As a fraction: 7
2
Use words Use a colon As a fraction

apples to oranges apples oranges apples 3
3 to 5 35 oranges 5

92

2. Build Understanding

Reading and Writing Ratios
Example: The baker buys 10 pounds of flour for every 1 pound of sugar.
Step 1: Identify the quantities you are comparing.

Flour 10 lbs, Sugar 1 lb

Step 2: Set up an equation to create a relationship. Flour 10
Sugar 1

Step 3: List alternate ways to write the ratio. Flour 10 to 1, 10:1, 10
Sugar 1

154 NUMINO Teacher s Guide