Add 40/12 and 5/21
1st number: 3 4/12, 2nd number: 5/21
40/12 + 5/21 is 25/7.
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,
40/12 = 40 × 7/12 × 7 = 280/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
5/21 = 5 × 4/21 × 4 = 20/84 - Add the two like fractions:
280/84 + 20/84 = 280 + 20/84 = 300/84 - 300/84 simplified gives 25/7
- So, 40/12 + 5/21 = 25/7
In mixed form: 34/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/12+5/21 40/12+10/21 40/24+5/21 40/12+5/42 40/12+15/21 40/36+5/21 40/12+5/63 40/12+25/21 40/60+5/21 40/12+35/21 40/84+5/21