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

Add 84/54 and 5/21

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

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

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

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