To convert the improper fraction 21/8 into a mixed number, we first divide the numerator (21) by the denominator (8).
When we divide 21 by 8, we find that 8 fits into 21 two times (2 x 8 = 16). The remainder from this division process is 21 – 16 = 5.
Now we can express the result as a mixed number. The whole number part is 2, and the fractional part is formed from the remainder (5) over the original denominator (8). So, 21/8 as a mixed number is:
2 5/8
In summary, 21 8 as a mixed number is 2 5/8.