ratios and proportions

Front

What is a ratio?

Back

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

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 the two ratios and set the products equal to each other.

Front

What does it mean if two ratios form a proportion?

Back

It means that the two ratios are equivalent, or that they represent the same relationship between quantities.

Front

If 3 apples cost $1.50, how much do 12 apples cost?

Back

$6.00 (Set up the proportion: 3/1.50 = 12/x, cross-multiply and solve for x).

Front

What is the formula for finding the unit rate?

Back

The unit rate is found by dividing the first quantity by the second quantity, expressed as 'quantity per 1 unit of another quantity'.

Front

How do you determine if two ratios are equivalent?

Back

Two ratios are equivalent if their cross products are equal.

Front

If a recipe calls for 2 cups of flour for every 3 cups of sugar, what is the ratio of flour to sugar?

Back

The ratio of flour to sugar is 2:3.

Front

What is the cost per pound of a 20-lb bag of dog food that costs $23.44?

Back

$1.17 per pound (23.44 / 20 = 1.17).

Front

If Gracie has 24 cookies for 3 classes, how many cookies per class does she have?

Back

8 cookies per class (24 cookies / 3 classes = 8 cookies/class).