Percent Proportions

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 a percentage of a number?

Back

To calculate a percentage of a number, multiply the number by the percentage (in decimal form). For example, to find 20% of 50, calculate 50 x 0.20 = 10.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, if a/b = c/d, then a, b, c, and d are in proportion.

Front

How do you find the percent of a total?

Back

To find the percent of a total, divide the part by the whole and then multiply by 100. For example, if 30 out of 200 students passed, the percent is (30/200) x 100 = 15%.

Front

What is 30% of 80?

Back

24

Front

If 60% of a number is 30, what is the number?

Back

50 (because 30 is 60% of 50).

Front

What is the formula for finding the percent increase?

Back

Percent Increase = ((New Value - Original Value) / Original Value) x 100.

Front

What is the formula for finding the percent decrease?

Back

Percent Decrease = ((Original Value - New Value) / Original Value) x 100.

Front

How do you convert a fraction to a percent?

Back

To convert a fraction to a percent, divide the numerator by the denominator and multiply by 100. For example, 1/4 = (1 ÷ 4) x 100 = 25%.

Front

What is 90% of 500?

Back

450