11 plus what equals 20?

This is how to calculate "11 plus what equals 20?" In other words, 11 plus a number equals 20. What is that number? We start by converting this word problem into an equation where "what" is what we want to solve:

11 + what = 20

To solve this equation, we first add -11 to each side of the equal sign like this:

11 - 11 + what = 20 - 11

Then, we do the calculation to get the answer to "11 plus what equals 20?" as follows:

What = 9

The answer to "11 plus what equals 20?" is 9. You know this answer is correct because 11 plus 9 equals 20.

Plus What Equals Calculator
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11 plus what equals 21?
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