Add 10/70 and 81/42, Solve 10/70 + 1 39/42 as a fraction

Add 10/70 and 81/42

1^st number: 10/70, 2^nd number: 1 39/42

10/70 + 81/42 is 29/14.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 42 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 70 × 3 = 210,
10/70 = 10 × 3/70 × 3 = 30/210
Likewise, for the 2nd fraction, since 42 × 5 = 210,
81/42 = 81 × 5/42 × 5 = 405/210
Add the two like fractions:
30/210 + 405/210 = 30 + 405/210 = 435/210
435/210 simplified gives 29/14
So, 10/70 + 81/42 = 29/14
In mixed form: 21/14

MathStep (Works offline)

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