Add 12/28 and 27/42, Solve 12/28 + 27/42 as a fraction

Add 12/28 and 27/42

12/28 + 27/42 is 15/14.

Find the least common denominator or LCM of the two denominators:
LCM of 28 and 42 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 28 × 3 = 84,
12/28 = 12 × 3/28 × 3 = 36/84
Likewise, for the 2nd fraction, since 42 × 2 = 84,
27/42 = 27 × 2/42 × 2 = 54/84
Add the two like fractions:
36/84 + 54/84 = 36 + 54/84 = 90/84
90/84 simplified gives 15/14
So, 12/28 + 27/42 = 15/14
In mixed form: 11/14

MathStep (Works offline)

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