Add 5/21 and 12/9
1st number: 5/21, 2nd number: 1 3/9
5/21 + 12/9 is 11/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 21 × 3 = 63,
5/21 = 5 × 3/21 × 3 = 15/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
12/9 = 12 × 7/9 × 7 = 84/63 - Add the two like fractions:
15/63 + 84/63 = 15 + 84/63 = 99/63 - 99/63 simplified gives 11/7
- So, 5/21 + 12/9 = 11/7
In mixed form: 14/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/21+12/9 5/21+24/9 5/42+12/9 5/21+12/18 15/21+12/9 5/21+36/9 5/63+12/9 5/21+12/27 25/21+12/9 5/21+60/9 5/21+12/45 35/21+12/9 5/21+84/9 5/21+12/63