Percent Proportions

Front

What is a percent?

Back

A percent is a ratio expressed as a fraction of 100. It represents how many parts out of 100 something is.

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 find the total when given a percentage and a part?

Back

To find the total when given a percentage and a part, divide the part by the percentage (in decimal form). For example, if 30% of a number is 15, then the total is 15 / 0.30 = 50.

Front

What is a ratio?

Back

A ratio is a comparison of two quantities, showing how many times one value contains or is contained within the other.

Front

How do you simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common divisor (GCD). For example, the ratio 10:15 simplifies to 2:3.

Front

What is the formula to find the percentage of a part compared to a whole?

Back

The formula is (part/whole) * 100 = percentage. For example, if you have 25 out of 100, the percentage is (25/100) * 100 = 25%.

Front

What is 34% of 150?

Back

51

Front

If a class has 15 boys and 20 girls, what is the boy:girl ratio in simplest form?

Back

3:4

Front

The hockey team won 63 out of 84 games. What percent of the games did the team win?

Back

75%.