Add 3/21 and 3/12
3/21 + 3/12 is 11/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
3/21 = 3 × 4/21 × 4 = 12/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
3/12 = 3 × 7/12 × 7 = 21/84 - Add the two like fractions:
12/84 + 21/84 = 12 + 21/84 = 33/84 - 33/84 simplified gives 11/28
- So, 3/21 + 3/12 = 11/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/21+3/12 3/21+6/12 3/42+3/12 3/21+3/24 9/21+3/12 3/21+9/12 3/63+3/12 3/21+3/36 15/21+3/12 3/21+15/12 3/21+3/60 3/21+21/12 3/21+3/84