Add 10/12 and 9/21
10/12 + 9/21 is 53/42.
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,
10/12 = 10 × 7/12 × 7 = 70/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
9/21 = 9 × 4/21 × 4 = 36/84 - Add the two like fractions:
70/84 + 36/84 = 70 + 36/84 = 106/84 - 106/84 simplified gives 53/42
- So, 10/12 + 9/21 = 53/42
In mixed form: 111/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/12+9/21 10/12+18/21 10/24+9/21 10/12+9/42 30/12+9/21 10/12+27/21 10/36+9/21 10/12+9/63 50/12+9/21 10/12+45/21 10/60+9/21 70/12+9/21 10/12+63/21 10/84+9/21