Add 4/15 and 28/21
1st number: 4/15, 2nd number: 1 7/21
4/15 + 28/21 is 8/5.
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,
4/15 = 4 × 7/15 × 7 = 28/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
28/21 = 28 × 5/21 × 5 = 140/105 - Add the two like fractions:
28/105 + 140/105 = 28 + 140/105 = 168/105 - 168/105 simplified gives 8/5
- So, 4/15 + 28/21 = 8/5
In mixed form: 13/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/15+28/21 4/15+56/21 4/30+28/21 4/15+28/42 12/15+28/21 4/15+84/21 4/45+28/21 4/15+28/63 20/15+28/21 4/75+28/21 28/15+28/21