Add 80/21 and 3/10, Solve 3 17/21 + 3/10 as a fraction

Add 80/21 and 3/10

1^st number: 3 17/21, 2^nd number: 3/10

80/21 + 3/10 is 863/210.

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,
80/21 = 80 × 10/21 × 10 = 800/210
Likewise, for the 2nd fraction, since 10 × 21 = 210,
3/10 = 3 × 21/10 × 21 = 63/210
Add the two like fractions:
800/210 + 63/210 = 800 + 63/210 = 863/210
So, 80/21 + 3/10 = 863/210
In mixed form: 423/210

MathStep (Works offline)

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