8 plus what equals 99?

This is how to calculate "8 plus what equals 99?" In other words, 8 plus a number equals 99. What is that number? We start by converting this word problem into an equation where "what" is what we want to solve:

8 + what = 99

To solve this equation, we first add -8 to each side of the equal sign like this:

8 - 8 + what = 99 - 8

Then, we do the calculation to get the answer to "8 plus what equals 99?" as follows:

What = 91

The answer to "8 plus what equals 99?" is 91. You know this answer is correct because 8 plus 91 equals 99.

Plus What Equals Calculator
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