Ratios Using Ratios Using DataData

RatioRatio is a comparison of two is a comparison of two numbers,numbers,

Usually written as a fraction Usually written as a fraction a/ba/b, where , where aa and and bb are the are the

numbersnumbers

First First number in the number in the numeratornumeratorSecondSecond number in the number in the

denominatordenominatorDifferent ways to write a ratio:Different ways to write a ratio:

3 to 43 to 4 3:4 ¾ 3 out of 4 3:4 ¾ 3 out of 4

All ratios should be in All ratios should be in reduced formreduced form

Finding RatiosFinding Ratios

Bag Bag MarblesMarbles

10 blue10 blue

15 yellow15 yellow

3 green3 green

1 purple1 purple

24 pink24 pink

Ratio blue to yellow

Ratio green to blue

Ratio green to yellow

Ratio purple to pink

Ratio blue to pink

Ratio purple to green

Ratio yellow to green

10/15 = 2/3

3/ 10

3/15 = 1/5

1/24

10/24 = 5/12

1/3

15/3 = 5/1

Our ClassroomOur Classroom

Ratio of girls to boysRatio of girls to boys

Ratio of boys to girlsRatio of boys to girls

Ratio of number students to teacherRatio of number students to teacher

Ratio of girls to number of studentsRatio of girls to number of students

Ratio of boys to number of studentsRatio of boys to number of students

Equal Ratios same as Equal Ratios same as Equivalent fractionsEquivalent fractions

12/15 = 4/512/15 = 4/5 24/30 = 4/524/30 = 4/5

10/16 = 5/810/16 = 5/8 24/48 = ½24/48 = ½

48/18 = 8/348/18 = 8/3 60/20 = 3/160/20 = 3/1

5/6 = 15/18 = 10/12 = 20/24 = 25/30 5/6 = 15/18 = 10/12 = 20/24 = 25/30 = 30/36= 30/36

Write each ratio in Write each ratio in simplest formsimplest form

25/7525/75

110/20110/20

12 to 4412 to 44

15 : 4015 : 40

1/31/3

11/211/2

3 to113 to11

3:83:8

Comparing RatiosComparing Ratios

You can use a decimal to express and You can use a decimal to express and compare ratioscompare ratios

¾ = .75¾ = .75

5 to 16 = .31255 to 16 = .3125

7:8 = .8757:8 = .875

5/16 < ¾ < 7/85/16 < ¾ < 7/8