Add 1/21 and 72/18, Solve 1/21 + 4 0/18 as a fraction

Add 1/21 and 72/18

1^st number: 1/21, 2^nd number: 4 0/18

1/21 + 72/18 is 85/21.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 21 × 6 = 126,
1/21 = 1 × 6/21 × 6 = 6/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
72/18 = 72 × 7/18 × 7 = 504/126
Add the two like fractions:
6/126 + 504/126 = 6 + 504/126 = 510/126
510/126 simplified gives 85/21
So, 1/21 + 72/18 = 85/21
In mixed form: 41/21

MathStep (Works offline)

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