Rates, Ratios, and Proportions

Front

What is a unit rate?

Back

A unit rate is a comparison of two different quantities where one of the quantities is expressed as one unit. For example, if 3 CDs cost $41.91, the unit rate is the cost per CD.

Front

How do you find the unit rate from a total cost?

Back

To find the unit rate, divide the total cost by the number of items. For example, $41.91 ÷ 3 CDs = $13.97 per CD.

Front

If there are 12 pencils in a pack, how many packs are needed for 108 pencils?

Back

To find the number of packs needed, divide the total number of pencils by the number of pencils per pack: 108 ÷ 12 = 9 packs.

Front

What is a ratio?

Back

A ratio is a relationship between two quantities, showing how many times one value contains or is contained within the other. For example, the ratio of 10 shaded squares to 6 not shaded squares is written as 10:6.

Front

How do you simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common factor. For example, the ratio 10:6 can be simplified to 5:3.

Front

What does it mean for two ratios to be proportional?

Back

Two ratios are proportional if they express the same relationship between quantities. For example, 3/4 and 24/32 are proportional because they simplify to the same value.

Front

How can you determine if two ratios are proportional?

Back

To determine if two ratios are proportional, cross-multiply and compare the products. If the products are equal, the ratios are proportional.

Front

What is the unit rate of $2.00 per dice compared to $0.20 per dice?

Back

$0.20 per dice is the correct unit rate, as it indicates the cost for one die.

Front

What is the formula for finding a unit rate?

Back

The formula for finding a unit rate is: Unit Rate = Total Quantity / Number of Units.

Front

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

Back

The ratio of flour to sugar is 2:3.