Percent Proportions

Front

What is a percent?

Back

A percent is a ratio expressed as a fraction of 100. It represents how much of something exists in relation to 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 * 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 convert a fraction to a percent?

Back

To convert a fraction to a percent, divide the numerator by the denominator and then multiply by 100. For example, 1/4 = 0.25 = 25%.

Front

What is the formula to find the whole when given a percent and a part?

Back

The formula is: Whole = Part / (Percent / 100). For example, if 30 is 20% of a number, then the whole is 30 / 0.20 = 150.

Front

What is the relationship between ratios and percentages?

Back

Ratios can be converted to percentages by dividing one part of the ratio by the total and multiplying by 100. For example, in the ratio 5:7, 5/(5+7) = 5/12 = 0.4167 = 41.67%.

Front

What is 34% of 150?

Back

51

Front

If a movie theater has 250 seats and 225 are sold, what percent of the seats are sold?

Back

90%

Front

Sarah earns $20 a day and spends 30% of it. How much does she spend?

Back

$6

Front

What is 90% of 250?

Back

225