Percent Proportions

Front

What is a percent?

Back

A percent is a ratio that compares a number to 100. It is often used to express how much of something there is in relation to a whole.

Front

How do you convert a fraction to a percent?

Back

To convert a fraction to a percent, divide the top number (numerator) by the bottom number (denominator) and then multiply the result by 100.

Front

What is the formula for finding a percent of a number?

Back

The formula is: Percent of a number = (Percent / 100) * Number.

Front

If 25% of a class of 40 students are girls, how many girls are in the class?

Back

10 girls. (25% of 40 = 0.25 * 40 = 10)

Front

What does it mean if a price is discounted by 20%?

Back

It means that the price is reduced by 20 out of every 100 units of the original price.

Front

How do you find the percent increase from 50 to 75?

Back

Percent Increase = ((New Value - Old Value) / Old Value) * 100. So, ((75 - 50) / 50) * 100 = 50% increase.

Front

What is a proportion?

Back

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

Front

How do you set up a proportion to solve for an unknown?

Back

Cross-multiply the two ratios and set them equal to each other to solve for the unknown.

Front

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

Back

The number is 50. (30 = 0.60 * Number, so Number = 30 / 0.60 = 50)

Front

What is the relationship between percent, fraction, and decimal?

Back

A percent can be converted to a fraction by placing it over 100 and simplifying. It can also be converted to a decimal by dividing by 100.