Add 1/12 and 63/42, Solve 1/12 + 1 21/42 as a fraction

Add 1/12 and 63/42

1^st number: 1/12, 2^nd number: 1 21/42

1/12 + 63/42 is 19/12.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 42 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 12 × 7 = 84,
1/12 = 1 × 7/12 × 7 = 7/84
Likewise, for the 2nd fraction, since 42 × 2 = 84,
63/42 = 63 × 2/42 × 2 = 126/84
Add the two like fractions:
7/84 + 126/84 = 7 + 126/84 = 133/84
133/84 simplified gives 19/12
So, 1/12 + 63/42 = 19/12
In mixed form: 17/12

MathStep (Works offline)

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