If there is one decimal place in each of two factors, then how many decimal places will the product have?

It will have 2 decimal places. You add up how many decimal places are in each factor and that is how many you will have in your product. Example: 2.1 x 2.5= 5.25

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.