Add 81/70 and 15/12, Solve 1 11/70 + 1 3/12 as a fraction

Add 81/70 and 15/12

1^st number: 1 11/70, 2^nd number: 1 3/12

81/70 + 15/12 is 337/140.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 12 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 70 × 6 = 420,
81/70 = 81 × 6/70 × 6 = 486/420
Likewise, for the 2nd fraction, since 12 × 35 = 420,
15/12 = 15 × 35/12 × 35 = 525/420
Add the two like fractions:
486/420 + 525/420 = 486 + 525/420 = 1011/420
1011/420 simplified gives 337/140
So, 81/70 + 15/12 = 337/140
In mixed form: 257/140

MathStep (Works offline)

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