Add 1/15 and 42/21
1st number: 1/15, 2nd number: 2 0/21
1/15 + 42/21 is 31/15.
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,
1/15 = 1 × 7/15 × 7 = 7/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
42/21 = 42 × 5/21 × 5 = 210/105 - Add the two like fractions:
7/105 + 210/105 = 7 + 210/105 = 217/105 - 217/105 simplified gives 31/15
- So, 1/15 + 42/21 = 31/15
In mixed form: 21/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/15+42/21 1/15+84/21 1/30+42/21 3/15+42/21 1/45+42/21 1/15+42/63 5/15+42/21 1/75+42/21 7/15+42/21