Add 21/9 and 12/21
1st number: 2 3/9, 2nd number: 12/21
21/9 + 12/21 is 61/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 21 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
21/9 = 21 × 7/9 × 7 = 147/63 - Likewise, for the 2nd fraction, since 21 × 3 = 63,
12/21 = 12 × 3/21 × 3 = 36/63 - Add the two like fractions:
147/63 + 36/63 = 147 + 36/63 = 183/63 - 183/63 simplified gives 61/21
- So, 21/9 + 12/21 = 61/21
In mixed form: 219/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/9+12/21 21/9+24/21 21/18+12/21 21/9+12/42 63/9+12/21 21/9+36/21 21/27+12/21 21/9+12/63 21/9+60/21 21/45+12/21 21/9+84/21 21/63+12/21