In the past two sections, you reviewed addition, subtraction, multiplication, and division. In this section, you will notice that when simplifying expressions, there is a specific mathematical order.

To begin this part of the lesson, use a calculator or app to simplify the following expression. Once you have done so, continue the lesson to see how other students simplified the expression.

Matt and Josey simplified the same expression below and got different results. Compare your solution to theirs.

**Knowing How to Determine the Correct Answer**

As you can see, it is possible to get different answers if we don’t have directions to follow. The directions used for simplifying expressions are called the order of operations.

In the above example, four operations were performed in the expression: subtraction, multiplication, addition, and division. How do you know which one to do first? Matt started on the left and worked straight through to the right. Josey started multiplying first. See the correct order of operations below.