Percent Proportions

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

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.

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.

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%.

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50 (because 30 is 60% of 50).

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

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

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%.

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