Add 28/42 and 21/10, Solve 28/42 + 2 1/10 as a fraction

Add 28/42 and 21/10

1^st number: 28/42, 2^nd number: 2 1/10

28/42 + 21/10 is 83/30.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 10 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 42 × 5 = 210,
28/42 = 28 × 5/42 × 5 = 140/210
Likewise, for the 2nd fraction, since 10 × 21 = 210,
21/10 = 21 × 21/10 × 21 = 441/210
Add the two like fractions:
140/210 + 441/210 = 140 + 441/210 = 581/210
581/210 simplified gives 83/30
So, 28/42 + 21/10 = 83/30
In mixed form: 223/30

MathStep (Works offline)

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