Percents & 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 the percent of a number?

Back

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

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. It can be used to solve for an unknown value.

Front

How do you set up a proportion?

Back

To set up a proportion, write two ratios as fractions and set them equal to each other. For example, if 30 is 20% of x, set it up as 30/x = 20/100.

Front

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

Back

The formula is: (Part/Whole) * 100 = Percent.

Front

If Chaz consumed 36 mg of vitamin C, what percent of the recommended 90 mg did he consume?

Back

40%.

Front

How do you find the total when given a part and a percent?

Back

Use the formula: Total = Part / (Percent in decimal form). For example, if 30 is 20% of x, then x = 30 / 0.20 = 150.

Front

What is the percent increase formula?

Back

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

Front

What is the percent decrease formula?

Back

Percent Decrease = ((Original Value - New Value) / Original Value) * 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) * 100 = 25%.