Add 28/30 and 81/7, Solve 28/30 + 11 4/7 as a fraction

Add 28/30 and 81/7

1^st number: 28/30, 2^nd number: 11 4/7

28/30 + 81/7 is 1313/105.

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

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 30 × 7 = 210,
28/30 = 28 × 7/30 × 7 = 196/210
Likewise, for the 2nd fraction, since 7 × 30 = 210,
81/7 = 81 × 30/7 × 30 = 2430/210
Add the two like fractions:
196/210 + 2430/210 = 196 + 2430/210 = 2626/210
2626/210 simplified gives 1313/105
So, 28/30 + 81/7 = 1313/105
In mixed form: 1253/105

MathStep (Works offline)

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