What is the result of subtracting 21 from 30?

To find the result of subtracting 21 from 30, you perform the calculation 30 - 21. By breaking this down:

First, take 30, which is the larger number in this problem. When you subtract 21, you can think of it in steps. From 30, if you remove 20, you are left with 10. Then, removing in the remaining 1 effectively means you subtract one more from that 10, resulting in a total of 9.

Thus, the result of subtracting 21 from 30 is 9. This is the mathematical process that confirms why the answer is indeed correct based on the calculation.