Intro to Proportions

Front

What is a proportion?

Back

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

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CCSS.7.RP.A.2A

Front

True or false: 6/7 = 15/14

Back

False

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CCSS.4.NF.A.2

Front

How do you determine if two ratios form a proportion?

Back

Two ratios form a proportion if their cross products are equal.

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CCSS.7.RP.A.2A

Front

What is the unit rate of 36 dogs in 3 cages?

Back

12 per cage

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CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

If the ratio of Gear A to Gear B is 5 to 12, how many teeth are on Gear B if Gear A has 15 teeth?

Back

36 teeth on Gear B.

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

What is the cross product of the ratios 2/3 and 4/6?

Back

The cross product is 2*6 = 12 and 3*4 = 12, so they are equal.

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CCSS.6.RP.A.3A

Front

If a recipe calls for 2 cups of flour for every 3 cups of sugar, what is the ratio of flour to sugar?

Back

The ratio of flour to sugar is 2:3.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

What is the unit rate of 60 miles in 3 hours?

Back

20 miles per hour.

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

Front

If the ratio of boys to girls in a class is 4:5 and there are 20 boys, how many girls are there?

Back

25 girls.