Add 70/21 and 27/72, Solve 3 7/21 + 27/72 as a fraction

Add 70/21 and 27/72

1^st number: 3 7/21, 2^nd number: 27/72

70/21 + 27/72 is 89/24.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 72 is 504

Next, find the equivalent fraction of both fractional numbers with denominator 504
For the 1st fraction, since 21 × 24 = 504,
70/21 = 70 × 24/21 × 24 = 1680/504
Likewise, for the 2nd fraction, since 72 × 7 = 504,
27/72 = 27 × 7/72 × 7 = 189/504
Add the two like fractions:
1680/504 + 189/504 = 1680 + 189/504 = 1869/504
1869/504 simplified gives 89/24
So, 70/21 + 27/72 = 89/24
In mixed form: 317/24

MathStep (Works offline)

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