Camila was out at a restaurant for dinner when the bill came. Her dinner came to $32. After adding in a tip, before tax, she paid $40. Find the percent tip.

This law is sometimes called the grouping property. as you can see, regardless of how the numbers are grouped, the answer is still 13. the associative law of multiplication is similar to the same law for addition. it says that no matter how you group numbers you are multiplying together, you will get the same answer.