Add 20/12 and 16/21
1st number: 1 8/12, 2nd number: 16/21
20/12 + 16/21 is 17/7.
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,
20/12 = 20 × 7/12 × 7 = 140/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
16/21 = 16 × 4/21 × 4 = 64/84 - Add the two like fractions:
140/84 + 64/84 = 140 + 64/84 = 204/84 - 204/84 simplified gives 17/7
- So, 20/12 + 16/21 = 17/7
In mixed form: 23/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/12+16/21 20/12+32/21 20/24+16/21 20/12+16/42 60/12+16/21 20/12+48/21 20/36+16/21 20/12+16/63 20/12+80/21 20/60+16/21 20/84+16/21