Add 70/15 and 18/21
1st number: 4 10/15, 2nd number: 18/21
70/15 + 18/21 is 116/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
70/15 = 70 × 7/15 × 7 = 490/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
18/21 = 18 × 5/21 × 5 = 90/105 - Add the two like fractions:
490/105 + 90/105 = 490 + 90/105 = 580/105 - 580/105 simplified gives 116/21
- So, 70/15 + 18/21 = 116/21
In mixed form: 511/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/15+36/21 70/30+18/21 70/15+18/42 70/15+54/21 70/45+18/21 70/15+18/63 70/15+90/21 70/75+18/21