PROPORTIONS

Front

What is a proportion?

Back

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

Front

How do you find a percentage of a number?

Back

To find 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 the formula to find the whole when given a part and a percentage?

Back

The formula is: Whole = Part / (Percentage in decimal form). For example, if 4.5 is 7.5% of a number, the whole is 4.5 / 0.075 = 60.

Front

If 60% of a number is 90, how do you find the number?

Back

Use the formula: Number = Part / (Percentage in decimal form). Here, Number = 90 / 0.60 = 150.

Front

What does it mean to solve for x in an equation?

Back

To solve for x means to find the value of x that makes the equation true.

Front

How do you calculate the remaining amount after a percentage loss?

Back

To calculate the remaining amount after a percentage loss, subtract the percentage from 100% and then multiply by the original amount. For example, if 60% is lost from 150, remaining = 150 * (1 - 0.60) = 60.

Front

What is the unit rate?

Back

The unit rate is a comparison of two different quantities when they are combined together. It is often expressed as a quantity per one unit of another quantity.

Front

How do you set up a proportion to solve a problem?

Back

To set up a proportion, write two ratios as fractions and set them equal to each other. For example, if 7 rolls cost $1.68, and you want to find the cost of 29 rolls, set it up as 7/1.68 = 29/x.

Front

What is cross-multiplication in proportions?

Back

Cross-multiplication is a method used to solve proportions by multiplying the numerator of one fraction by the denominator of the other fraction.

Front

If 7 sandwich rolls cost $1.68, what is the cost of one roll?

Back

To find the cost of one roll, divide the total cost by the number of rolls: $1.68 / 7 = $0.24.