Add 5/21 and 36/9, Solve 5/21 + 4 0/9 as a fraction

Add 5/21 and 36/9

1^st number: 5/21, 2^nd number: 4 0/9

5/21 + 36/9 is 89/21.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63

Next, find the equivalent fraction of both fractional numbers with denominator 63
For the 1st fraction, since 21 × 3 = 63,
5/21 = 5 × 3/21 × 3 = 15/63
Likewise, for the 2nd fraction, since 9 × 7 = 63,
36/9 = 36 × 7/9 × 7 = 252/63
Add the two like fractions:
15/63 + 252/63 = 15 + 252/63 = 267/63
267/63 simplified gives 89/21
So, 5/21 + 36/9 = 89/21
In mixed form: 45/21

MathStep (Works offline)

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