Add 7/27 and 70/21, Solve 7/27 + 3 7/21 as a fraction

Add 7/27 and 70/21

1^st number: 7/27, 2^nd number: 3 7/21

7/27 + 70/21 is 97/27.

Find the least common denominator or LCM of the two denominators:
LCM of 27 and 21 is 189

Next, find the equivalent fraction of both fractional numbers with denominator 189
For the 1st fraction, since 27 × 7 = 189,
7/27 = 7 × 7/27 × 7 = 49/189
Likewise, for the 2nd fraction, since 21 × 9 = 189,
70/21 = 70 × 9/21 × 9 = 630/189
Add the two like fractions:
49/189 + 630/189 = 49 + 630/189 = 679/189
679/189 simplified gives 97/27
So, 7/27 + 70/21 = 97/27
In mixed form: 316/27

MathStep (Works offline)

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