Ratio

2009

Leslie Paytes

Ratio*- a comparison of two quantities using division

*(The word ratio comes from the Latin word ratus which means "calculation." In the middle ages the word ratio was used to mean "computation.")

Count the coins to compare the number of pennies to the number of nickles.

# of pennies =# of nickles =

Pull

Pullusing the word "to"

between the two numbers 5 to 3

Pull

Pull

as a fraction 5/3

Pull

Pull

Use a colon between the two numbers 5:3

Compare the number of pennies to nicklesThere are three different ways to write a ratio when comparing a part to a part...

All three are read5 to 3

Move coins for more info!

15/1315 to 1315:13

Suppose you wanted to compare the number of boys to girls in a class that had 15 boys and 13 girls. The first quantity in this case the boys is always written first

Move the Mathman to reveal the answer

13/1513 to 1513:15

Notice with the same numbers 15 boys and 13 girls, a comparision of girls to boys would yield an entirely different answer

Move the Mathman to reveal the answer

add numbers to find total

15/28 15 to 2815:2815 out of 28

Suppose you wanted to compare the number of boys to the total number of students in a class that had 15 boys and 13 girls. The first quantity in this case the boys is always written first.

Move Mathman to reveal an additional way to write ratios

Hint!