Proportions and Percent Change

Front

What is a proportion?

Back

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

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 25% of 200, calculate 200 * 0.25 = 50.

Front

What is percent change?

Back

Percent change is a way to express a change in value as a percentage of the original value. It is calculated as ((new value - old value) / old value) * 100.

Front

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

Back

To find the total number when given a percentage and the part, divide the part by the percentage (in decimal form). For example, if 34% of a number is 51, the total number is 51 / 0.34 = 150.

Front

What is the formula for calculating the percentage score on a test?

Back

The formula for calculating the percentage score is (number of correct answers / total number of questions) * 100.

Front

If 25% of a group is a certain category, how do you find the number in that category?

Back

To find the number in that category, multiply the total number in the group by 0.25 (the decimal equivalent of 25%).

Front

What is the relationship between fractions and percentages?

Back

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

Front

How do you express a number as a percentage of another number?

Back

To express a number as a percentage of another number, divide the first number by the second number and multiply by 100. For example, to express 50 as a percentage of 200, calculate (50 / 200) * 100 = 25%.

Front

What is the first step in solving a percent change problem?

Back

The first step in solving a percent change problem is to determine the original value and the new value.

Front

How do you calculate the number of items in a larger group based on a smaller group's percentage?

Back

To calculate the number of items in a larger group based on a smaller group's percentage, multiply the total number of items in the larger group by the percentage (in decimal form).