ratios and proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities, showing how many times one value contains or is contained within the other.

Front

How do you simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common divisor (GCD).

Front

What is a proportion?

Back

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

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply and then divide to find the unknown value.

Front

What is the cost per pound?

Back

Cost per pound is calculated by dividing the total cost by the weight in pounds.

Front

If a bag of dog food costs $23.44 for 20 lbs, what is the cost per pound?

Back

Cost per pound = $23.44 / 20 lbs = $1.172, rounded to $1.17.

Front

What is the ratio of girls to boys in a class with 32 girls and 16 boys?

Back

Front

What does it mean for a relationship to be proportional?

Back

A relationship is proportional if two quantities maintain a constant ratio.

Front

How can you tell if a table shows a proportional relationship?

Back

If the ratios of corresponding values are equal, the relationship is proportional.

Front

What is the first step in solving a proportion?

Back

The first step is to cross-multiply the two ratios.