Add 90/9 and 21/8, Solve 10 0/9 + 2 5/8 as a fraction

Add 90/9 and 21/8

1^st number: 10 0/9, 2^nd number: 2 5/8

90/9 + 21/8 is 101/8.

Find the least common denominator or LCM of the two denominators:
LCM of 9 and 8 is 72

Next, find the equivalent fraction of both fractional numbers with denominator 72
For the 1st fraction, since 9 × 8 = 72,
90/9 = 90 × 8/9 × 8 = 720/72
Likewise, for the 2nd fraction, since 8 × 9 = 72,
21/8 = 21 × 9/8 × 9 = 189/72
Add the two like fractions:
720/72 + 189/72 = 720 + 189/72 = 909/72
909/72 simplified gives 101/8
So, 90/9 + 21/8 = 101/8
In mixed form: 125/8

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad