ratios and proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities expressed as a fraction, indicating how many times one value contains or is contained within the other.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Tags

CCSS.7.RP.A.2A

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the two ratios and set the products equal to each other.

Tags

CCSS.7.RP.A.3

Front

If 5 cups of flour make 3 pies, how many cups of flour are needed for 1 pie?

Back

1.67 cups of flour are needed for 1 pie.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

If 5 cups of flour make 3 pies, how many pies can be made with 25 cups of flour?

Back

15 pies can be made with 25 cups of flour.

Tags

CCSS.6.RP.A.3B

Front

What does it mean if two ratios form a proportion?

Back

It means that the two ratios are equivalent, and the cross-products are equal.

Tags

CCSS.7.RP.A.2A

Front

What is the cross-multiplication method?

Back

The cross-multiplication method involves multiplying the numerator of one ratio by the denominator of the other ratio and vice versa.

Tags

CCSS.6.RP.A.3A

Front

If a:b = 2:3, what is the value of a if b = 9?

Back

a = 6.

Front

What is an equivalent ratio?

Back

An equivalent ratio is a ratio that expresses the same relationship between two quantities, even if the numbers are different.

Tags

CCSS.6.RP.A.3A

Front

How can you determine if two ratios are equivalent?

Back

You can determine if two ratios are equivalent by simplifying them to their lowest terms or by cross-multiplying.

Tags

CCSS.6.RP.A.3A