20 plus what equals 30?

This is how to calculate "20 plus what equals 30?" In other words, 20 plus a number equals 30. What is that number? We start by converting this word problem into an equation where "what" is what we want to solve:

20 + what = 30

To solve this equation, we first add -20 to each side of the equal sign like this:

20 - 20 + what = 30 - 20

Then, we do the calculation to get the answer to "20 plus what equals 30?" as follows:

What = 10

The answer to "20 plus what equals 30?" is 10. You know this answer is correct because 20 plus 10 equals 30.

Plus What Equals Calculator
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20 plus what equals 31?
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