Add 21/15 and 8/21
1st number: 1 6/15, 2nd number: 8/21
21/15 + 8/21 is 187/105.
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,
21/15 = 21 × 7/15 × 7 = 147/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
8/21 = 8 × 5/21 × 5 = 40/105 - Add the two like fractions:
147/105 + 40/105 = 147 + 40/105 = 187/105 - So, 21/15 + 8/21 = 187/105
In mixed form: 182/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+8/21 21/15+16/21 21/30+8/21 21/15+8/42 63/15+8/21 21/15+24/21 21/45+8/21 21/15+8/63 21/15+40/21 21/75+8/21 21/15+56/21