2 5/8. To find the mixed number, find out how many times 21 can go into 8. 21 can go into 8 2 times. So you know that two is the whole number for the mixed number. 8 x 2 = 16.
Subtract 16 from 21 to get your remainder. 21-16=5
That is your new numerator.
The denominator, 8, will always stay the same.
21/8 as a mixed number is 2 5/8.
