4 plus what equals 9?

This is how to calculate "4 plus what equals 9?" In other words, 4 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:

4 + what = 9

To solve this equation, we first add -4 to each side of the equal sign like this:

4 - 4 + what = 9 - 4

Then, we do the calculation to get the answer to "4 plus what equals 9?" as follows:

What = 5

The answer to "4 plus what equals 9?" is 5. You know this answer is correct because 4 plus 5 equals 9.

Plus What Equals Calculator
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4 plus what equals 10?
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