What is 8/10 - 9/10?

Here's how to subtract 9/10 from 8/10:

Step 1

Since our denominators match, we can subtract the numerators.

8 − 9 = -1

So the answer is:

Step 2

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

No good. 2 is larger than -1. So we're done reducing.