Add 3/5 and 28/21
1st number: 3/5, 2nd number: 1 7/21
3/5 + 28/21 is 29/15.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 5 × 21 = 105,
3/5 = 3 × 21/5 × 21 = 63/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
28/21 = 28 × 5/21 × 5 = 140/105 - Add the two like fractions:
63/105 + 140/105 = 63 + 140/105 = 203/105 - 203/105 simplified gives 29/15
- So, 3/5 + 28/21 = 29/15
In mixed form: 114/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/5+28/21 3/5+56/21 3/10+28/21 3/5+28/42 9/5+28/21 3/5+84/21 3/15+28/21 3/5+28/63 15/5+28/21 3/25+28/21 21/5+28/21 3/35+28/21