Add 10/15 and 42/21
1st number: 10/15, 2nd number: 2 0/21
10/15 + 42/21 is 8/3.
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,
10/15 = 10 × 7/15 × 7 = 70/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
42/21 = 42 × 5/21 × 5 = 210/105 - Add the two like fractions:
70/105 + 210/105 = 70 + 210/105 = 280/105 - 280/105 simplified gives 8/3
- So, 10/15 + 42/21 = 8/3
In mixed form: 22/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/15+42/21 10/15+84/21 10/30+42/21 30/15+42/21 10/45+42/21 10/15+42/63 50/15+42/21 10/75+42/21 70/15+42/21