Precent and Proportions

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 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 x 0.20 = 10.

Front

What does it mean to find 'what number' in a percent problem?

Back

It means to determine the total or whole amount when given a part and its percentage.

Front

If 20 is 40% of what number, how do you find that number?

Back

Divide the part (20) by the percentage (0.40). So, 20 ÷ 0.40 = 50.

Front

What is a proportion?

Back

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

Front

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

Back

Set up the equation as a fraction equal to another fraction, then cross-multiply to solve for the unknown.

Front

What is the formula for calculating the sale price after a discount?

Back

Sale Price = Original Price - (Original Price x Discount Rate).

Front

If a dress shirt costs $75 and has a 20% discount, what is the sale price?

Back

Sale Price = $75 - ($75 x 0.20) = $60.

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 x 100 = 25%.

Front

How do you find the percentage increase or decrease?

Back

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