Proportions: Word Problems

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 for x in a proportion?

Back

To solve for x in a proportion, cross-multiply the two ratios and then solve the resulting equation.

Tags

CCSS.7.RP.A.2C

Front

If 3 out of 5 teachers wore college shirts and 21 teachers wore college shirts, how do you find the total number of teachers?

Back

Set up the proportion: 3/5 = 21/x, then cross-multiply and solve for x.

Tags

CCSS.7.RP.A.2C

Front

What is the cross-multiplication method?

Back

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

Tags

CCSS.7.RP.A.3

Front

If 3 eggs are needed for 24 muffins, how many eggs are needed for 144 muffins?

Back

Set up the proportion: 3/24 = x/144, then cross-multiply and solve for x. The answer is 18 eggs.

Tags

CCSS.7.RP.A.3

Front

What does it mean for two ratios to be equivalent?

Back

Two ratios are equivalent if they represent the same relationship between quantities.

Tags

CCSS.6.RP.A.3A

Front

How can you check if two ratios are equivalent?

Back

You can check if two ratios are equivalent by cross-multiplying and seeing if the products are equal.

Tags

CCSS.6.RP.A.3A

Front

What is the formula for finding a missing value in a proportion?

Back

The formula is a/b = c/d, where a, b, c, and d are the values in the proportion. To find the missing value, cross-multiply and solve.

Tags

CCSS.7.RP.A.2C

Front

What is a ratio?

Back

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

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

How do you set up a proportion from a word problem?

Back

Identify the two ratios in the problem and set them equal to each other.

Tags

CCSS.7.RP.A.2C