Cross Multiplication Practice

Front

What is cross multiplication?

Back

Cross multiplication is a method used to solve proportions by multiplying the numerator of one fraction by the denominator of the other fraction.

Tags

CCSS.7.RP.A.3

Front

How do you set up a proportion?

Back

A proportion is set up by creating an equation that states two ratios are equal, typically in the form a/b = c/d.

Tags

CCSS.7.RP.A.3

Front

If 12 out of 100 scholars like pizza, what is the ratio of scholars who like pizza?

Back

The ratio is 12:100, which can be simplified to 3:25.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

How do you find the total number of scholars surveyed if 54 like pizza and the ratio is 12:100?

Back

Set up the proportion 12/100 = 54/x and solve for x, which gives x = 450.

Tags

CCSS.7.RP.A.3

Front

What is the total amount of paint used if the ratio of black to white paint is 6:8 and 27 cups of black paint are used?

Back

If 27 cups of black paint are used, the total paint used is 63 cups (27 cups black + 36 cups white).

Front

How do you calculate the amount of Sprite needed for 36 guests if 5 liters are needed for every 12 guests?

Back

Set up the proportion 5/12 = x/36 and solve for x, which gives x = 15 liters.

Tags

CCSS.7.RP.A.2B

Front

What is the ratio of students who enjoy basketball if 2 out of 10 students do?

Back

The ratio is 2:10, which simplifies to 1:5.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

How many students enjoy basketball in a class of 25 if the ratio is 2:10?

Back

Using the ratio, 25 students * (2/10) = 5 students enjoy basketball.

Front

If there are 4 pairs of crocs for every 8 pairs of sneakers, what is the ratio of crocs to sneakers?

Back

The ratio is 4:8, which simplifies to 1:2.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

How many pairs of crocs does Isaiah have if he has 6 pairs of sneakers?

Back

Using the ratio, 6 sneakers * (4/8) = 3 pairs of crocs.

Tags

CCSS.6.RP.A.3B