Add 10/21 and 15/10, Solve 10/21 + 1 5/10 as a fraction

Add 10/21 and 15/10

1^st number: 10/21, 2^nd number: 1 5/10

10/21 + 15/10 is 83/42.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 10 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 21 × 10 = 210,
10/21 = 10 × 10/21 × 10 = 100/210
Likewise, for the 2nd fraction, since 10 × 21 = 210,
15/10 = 15 × 21/10 × 21 = 315/210
Add the two like fractions:
100/210 + 315/210 = 100 + 315/210 = 415/210
415/210 simplified gives 83/42
So, 10/21 + 15/10 = 83/42
In mixed form: 141/42

MathStep (Works offline)

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