Percent Proportion Review

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 50 * 0.20 = 10.

Front

What is the formula for finding the whole when given a percent and a part?

Back

The formula is: Whole = Part / (Percent / 100). For example, if 34% of a number is 51, the whole is 51 / 0.34 = 150.

Front

How do you find the percent increase or decrease?

Back

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

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, a/b = c/d.

Front

How do you set up a proportion to solve for an unknown?

Back

To set up a proportion, write the known ratios as fractions and set them equal to each other. For example, if 40% of x is 20, set up the proportion: 40/100 = 20/x.

Front

What does it mean if a student is part of 40% of a class?

Back

It means that the student is part of a group that represents 40 out of every 100 students in that class.

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 = 0.25 * 100 = 25%.

Front

If a movie theater has 250 seats and 225 are sold, how do you find the percent of empty seats?

Back

To find the percent of empty seats, first find the number of empty seats (250 - 225 = 25). Then, calculate (Empty Seats / Total Seats) * 100 = (25 / 250) * 100 = 10%.

Front

What is the relationship between part, whole, and percent?

Back

The relationship is defined by the formula: Percent = (Part / Whole) * 100.