Understanding Ratios

Front

What is a ratio?

Back

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

Front

How do you write a ratio?

Back

Ratios can be written in three ways: using a colon (e.g., 3:2), as a fraction (e.g., 3/2), or with the word 'to' (e.g., 3 to 2).

Front

If the ratio of up votes to down votes is 9:8 and there are 54 up votes, how do you find the number of down votes?

Back

To find the number of down votes, set up a proportion: 9/8 = 54/x. Cross-multiply and solve for x to find that there are 48 down votes.

Front

What is the relationship between ratios and fractions?

Back

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

Front

If the ratio of shoes sold to sandals sold is 9:5 and 72 shoes were sold, how do you find the number of sandals sold?

Back

Set up a proportion: 9/5 = 72/x. Cross-multiply and solve for x to find that 40 sandals were sold.

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 unit rate?

Back

A unit rate is a ratio that compares a quantity to one unit of another quantity, often expressed as 'per' (e.g., miles per hour).

Front

If a movie theater uses 7 cups of oil for every 5 batches of popcorn, how much oil is used for 40 batches?

Back

Set up a proportion: 7/5 = x/40. Cross-multiply to find that 56 cups of oil are used.

Front

What is the formula to find the total number of parts in a ratio?

Back

Add the numbers in the ratio together. For example, in the ratio 9:4, the total number of parts is 9 + 4 = 13.

Front

If the ratio of boys to girls is 9:4 and there are 36 boys, how do you find the number of girls?

Back

Set up a proportion: 9/4 = 36/x. Cross-multiply and solve for x to find that there are 16 girls.