Add 14/30 and 81/21, Solve 14/30 + 3 18/21 as a fraction

Add 14/30 and 81/21

1^st number: 14/30, 2^nd number: 3 18/21

14/30 + 81/21 is 454/105.

Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 30 × 7 = 210,
14/30 = 14 × 7/30 × 7 = 98/210
Likewise, for the 2nd fraction, since 21 × 10 = 210,
81/21 = 81 × 10/21 × 10 = 810/210
Add the two like fractions:
98/210 + 810/210 = 98 + 810/210 = 908/210
908/210 simplified gives 454/105
So, 14/30 + 81/21 = 454/105
In mixed form: 434/105

MathStep (Works offline)

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