ratios and proportions

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division, expressing how much of one quantity exists in relation to another.

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 terms and then solve for the unknown variable.

Front

What does it mean for two quantities to be proportional?

Back

Two quantities are proportional if they maintain a constant ratio or rate.

Front

What is the formula for finding a unit rate?

Back

The unit rate is found by dividing the quantity by the number of units, expressed as 'quantity per unit'.

Front

If 24 cookies are shared among 3 classes, how many cookies does each class get?

Back

Each class gets 8 cookies (24 cookies ÷ 3 classes = 8 cookies per class).

Front

If Gracie has 4 classes and wants to maintain the same ratio of cookies per class as before, how many cookies should she bring?

Back

Gracie should bring 32 cookies (8 cookies per class × 4 classes = 32 cookies).

Front

How do you find the price per gallon of gas if you know the total cost and the number of gallons?

Back

Divide the total cost by the number of gallons to find the price per gallon.

Front

What is the price per gallon if it costs $46.80 to fill a 13-gallon tank?

Back

The price per gallon is $3.60 ($46.80 ÷ 13 gallons = $3.60 per gallon).

Front

What is the relationship between ratios and fractions?

Back

Ratios can be expressed as fractions, where the first quantity is the numerator and the second quantity is the denominator.