Add 4/12 and 5/21
4/12 + 5/21 is 4/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
4/12 = 4 × 7/12 × 7 = 28/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
5/21 = 5 × 4/21 × 4 = 20/84 - Add the two like fractions:
28/84 + 20/84 = 28 + 20/84 = 48/84 - 48/84 simplified gives 4/7
- So, 4/12 + 5/21 = 4/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/12+5/21 4/12+10/21 4/24+5/21 4/12+5/42 4/12+15/21 4/36+5/21 4/12+5/63 20/12+5/21 4/12+25/21 4/60+5/21 28/12+5/21 4/12+35/21 4/84+5/21