Order of Operations: Addition and Subtraction

When looking at an equation - from left to right - after you've solved with what's inside any parentheses, and after you've solved any multiplication and division equations, you must do addition and subtraction equation.

Here's what you've learned up to now:

* Go from left to right and do any equations that are inside parentheses.

* Start again from the left and go from left to right and do any multiplication and division equations.

* Start again from the left and go from left to right and do any addition and subtraction equations.

Here's an example:

(1 × 3) + 8

Going from left to right, we see 1 × 3 inside parentheses. 1 × 3 = 3. So, our equation becomes:

3 + 8

which equals 11.

Here's another example:

12 - (7 + 1)

Again, we start from the left and go from left to right to search for parentheses. 8 is not a parenthesis. The first / sign is not a parenthesis. However, we then come to a set of parentheses that enclose the equation: 7 + 1. We know that 7 + 1 is 8. So, our equation becomes:

12 - 8

which equals 4.