Add 27/7 and 21/30, Solve 3 6/7 + 21/30 as a fraction

Add 27/7 and 21/30

1^st number: 3 6/7, 2^nd number: 21/30

27/7 + 21/30 is 319/70.

Find the least common denominator or LCM of the two denominators:
LCM of 7 and 30 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 7 × 30 = 210,
27/7 = 27 × 30/7 × 30 = 810/210
Likewise, for the 2nd fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210
Add the two like fractions:
810/210 + 147/210 = 810 + 147/210 = 957/210
957/210 simplified gives 319/70
So, 27/7 + 21/30 = 319/70
In mixed form: 439/70

MathStep (Works offline)

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