Add 5/21 and 84/54, Solve 5/21 + 1 30/54 as a fraction

Add 5/21 and 84/54

1^st number: 5/21, 2^nd number: 1 30/54

5/21 + 84/54 is 113/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 21 × 18 = 378,
5/21 = 5 × 18/21 × 18 = 90/378
Likewise, for the 2nd fraction, since 54 × 7 = 378,
84/54 = 84 × 7/54 × 7 = 588/378
Add the two like fractions:
90/378 + 588/378 = 90 + 588/378 = 678/378
678/378 simplified gives 113/63
So, 5/21 + 84/54 = 113/63
In mixed form: 150/63

MathStep (Works offline)

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