Add 1/15 and 1/21
1/15 + 1/21 is 4/35.
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,
1/21 = 1 × 5/21 × 5 = 5/105 - Add the two like fractions:
7/105 + 5/105 = 7 + 5/105 = 12/105 - 12/105 simplified gives 4/35
- So, 1/15 + 1/21 = 4/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/15+1/21 1/15+2/21 1/30+1/21 1/15+1/42 3/15+1/21 1/15+3/21 1/45+1/21 1/15+1/63 5/15+1/21 1/15+5/21 1/75+1/21 7/15+1/21 1/15+7/21