Add 20/12 and 63/21
1st number: 1 8/12, 2nd number: 3 0/21
20/12 + 63/21 is 14/3.
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,
63/21 = 63 × 4/21 × 4 = 252/84 - Add the two like fractions:
140/84 + 252/84 = 140 + 252/84 = 392/84 - 392/84 simplified gives 14/3
- So, 20/12 + 63/21 = 14/3
In mixed form: 42/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/12+63/21 20/24+63/21 20/12+63/42 60/12+63/21 20/36+63/21 20/60+63/21 20/84+63/21