You can't. That is a proper fraction. You can only turn improper fractions into mixed numbers
The mixed number for 21 over 8 is 25/8
21 over 20 as a mixed number = 11/20
225% as a mixed number is 21/4
5 over 2 as a mixed number is 21/2
The mixed number for 21/4 is 5 1/4.
The mixed number of 21 over 9 is 21/3
21 over 10 as a mixed number is 21/10
21 over 20 as a mixed number = 11/20
The mixed number for 21 over 8 is 25/8
Two and five eighths 21 = 8 + 8 + 5
225% as a mixed number is 21/4
5 over 2 as a mixed number is 21/2
45 over 18 as a mixed number = 21/2
The mixed number for 17 over 8 is 21/8
23 over 11 as a mixed number is 21/11
102 over 50 as a mixed number is: 21/25
The mixed number for 108 over 48 is 21/4