Add 81/28 and 21/10, Solve 2 25/28 + 2 1/10 as a fraction

Add 81/28 and 21/10

1^st number: 2 25/28, 2^nd number: 2 1/10

81/28 + 21/10 is 699/140.

Find the least common denominator or LCM of the two denominators:
LCM of 28 and 10 is 140

Next, find the equivalent fraction of both fractional numbers with denominator 140
For the 1st fraction, since 28 × 5 = 140,
81/28 = 81 × 5/28 × 5 = 405/140
Likewise, for the 2nd fraction, since 10 × 14 = 140,
21/10 = 21 × 14/10 × 14 = 294/140
Add the two like fractions:
405/140 + 294/140 = 405 + 294/140 = 699/140
So, 81/28 + 21/10 = 699/140
In mixed form: 4139/140

MathStep (Works offline)

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