There is a group of 15 people are ordering pizza. Each person wants 2 slices and each pizza has 10 slices. How many pizzas should they order?

3 pizzas

Step-by-step explanation:

First, we can calculate how many slices are necessary. Each person wants two slices, so for each person, we must add 2 slices. We can add 2 15 times, or multiply 2 by 15 to get 2 * 15 = 30

We now know that we need 30 slices of pizza. Next, we need to figure out how many pizzas we need given this information.

For each pizza, we can add 10 slices, as there are 10 slices of pizza.

For the first pizza, we have 10 slices

For the second, we have 10+10 = 20 slices

For the third, we have 10+10+10 = 10 * 3 = 30 slices. Perfect!

Another way of figuring out the number of pizzas we need would be to divide 30 by 10, and 30/10=3 would equal the number of pizzas. We need to figure out how many pizzas we need to have 30 slices, so we can divide here.

associative property of multiplication