13 plus what equals 9?

This is how to calculate "13 plus what equals 9?" In other words, 13 plus a number equals 9. What is that number? We start by converting this word problem into an equation where "what" is what we want to solve:

13 + what = 9

To solve this equation, we first add -13 to each side of the equal sign like this:

13 - 13 + what = 9 - 13

Then, we do the calculation to get the answer to "13 plus what equals 9?" as follows:

What = -4

The answer to "13 plus what equals 9?" is -4. You know this answer is correct because 13 plus -4 equals 9.

Plus What Equals Calculator
Here you can calculate a similar problem:

13 plus what equals 10?
Do you think you can solve a similar problem on your own? Try to figure out the next problem on our list and then go here to check the answer.