Ratios, Proportions, Unit Rates, and Percents

Front

What is a ratio?

Back

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

Front

How do you convert yards to feet?

Back

To convert yards to feet, multiply the number of yards by 3, since 1 yard equals 3 feet.

Front

What is a proportion?

Back

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

Front

How do you find the unit rate?

Back

To find the unit rate, divide the total quantity by the number of units. For example, if 5 books cost $15, the unit rate is $15 ÷ 5 = $3 per book.

Front

What is a percent?

Back

A percent is a ratio expressed as a fraction of 100. It represents a part of a whole.

Front

How do you calculate the percent of a quantity?

Back

To calculate the percent of a quantity, divide the part by the whole and then multiply by 100. For example, if 225 out of 250 seats are sold, the percent sold is (225 ÷ 250) × 100 = 90%.

Front

What is the formula for finding the total number of items when given a percent?

Back

If you know the percent and the number of items that corresponds to that percent, you can find the total number of items by dividing the part by the percent (in decimal form).

Front

What is the relationship between ratios and proportions?

Back

Ratios can be used to create proportions. If two ratios are equivalent, they form a proportion.

Front

How do you express a ratio in simplest form?

Back

To express a ratio in simplest form, divide both terms of the ratio by their greatest common factor.

Front

What is the cost per item if you know the total cost and the number of items?

Back

The cost per item is found by dividing the total cost by the number of items. For example, if 5 oranges cost $5, the cost per orange is $5 ÷ 5 = $1.