Proportions and Percents

Front

What is a proportion?

Back

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

Front

How do you calculate a percent of a number?

Back

To calculate a percent of a number, multiply the number by the percent (in decimal form). For example, to find 30% of 200, calculate 200 x 0.30 = 60.

Front

What is the formula for finding the unit rate?

Back

The unit rate is found by dividing the total amount by the number of units. For example, if you spend $40 on 5 pounds of concrete, the unit rate is $40 ÷ 5 = $8 per pound.

Front

What does it mean if two quantities are proportional?

Back

Two quantities are proportional if they maintain a constant ratio or rate.

Front

How do you convert a percentage to a decimal?

Back

To convert a percentage to a decimal, divide the percentage by 100. For example, 25% becomes 0.25.

Front

What is 40% of 200?

Back

40% of 200 is 80.

Front

If Sarah earns $20 a day and spends 30% of it, how much does she spend?

Back

Sarah spends $6.

Front

What is the relationship between fractions and percentages?

Back

Fractions can be converted to percentages by multiplying by 100. For example, 1/4 = 0.25 = 25%.

Front

How do you find the total amount if you know the percent and the part?

Back

To find the total amount, divide the part by the percent (in decimal form). For example, if 30 is 20% of a number, the total is 30 ÷ 0.20 = 150.

Front

What is the difference between proportional and non-proportional relationships?

Back

Proportional relationships have a constant ratio, while non-proportional relationships do not.