Add 1/42 and 90/12, Solve 1/42 + 7 6/12 as a fraction

Add 1/42 and 90/12

1^st number: 1/42, 2^nd number: 7 6/12

1/42 + 90/12 is 158/21.

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

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 42 × 2 = 84,
1/42 = 1 × 2/42 × 2 = 2/84
Likewise, for the 2nd fraction, since 12 × 7 = 84,
90/12 = 90 × 7/12 × 7 = 630/84
Add the two like fractions:
2/84 + 630/84 = 2 + 630/84 = 632/84
632/84 simplified gives 158/21
So, 1/42 + 90/12 = 158/21
In mixed form: 711/21

MathStep (Works offline)

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