Add 54/12 and 21/7, Solve 4 6/12 + 3 0/7 as a fraction

Add 54/12 and 21/7

1^st number: 4 6/12, 2^nd number: 3 0/7

54/12 + 21/7 is 15/2.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 7 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 12 × 7 = 84,
54/12 = 54 × 7/12 × 7 = 378/84
Likewise, for the 2nd fraction, since 7 × 12 = 84,
21/7 = 21 × 12/7 × 12 = 252/84
Add the two like fractions:
378/84 + 252/84 = 378 + 252/84 = 630/84
630/84 simplified gives 15/2
So, 54/12 + 21/7 = 15/2
In mixed form: 71/2

MathStep (Works offline)

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