For example( and this is straight from the paper), "15 people in 3 equal rows."

At a race, there are 3 rows with 15 people in each row. How many total people are there?

Numerical expression- 15 times 3

(Idk if this helped very much but it's worth a shot)

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.

The answer is