Add 21/12 and 1/21
1st number: 1 9/12, 2nd number: 1/21
21/12 + 1/21 is 151/84.
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,
21/12 = 21 × 7/12 × 7 = 147/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
1/21 = 1 × 4/21 × 4 = 4/84 - Add the two like fractions:
147/84 + 4/84 = 147 + 4/84 = 151/84 - So, 21/12 + 1/21 = 151/84
In mixed form: 167/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/12+1/21 21/12+2/21 21/24+1/21 21/12+1/42 63/12+1/21 21/12+3/21 21/36+1/21 21/12+1/63 21/12+5/21 21/60+1/21 21/12+7/21 21/84+1/21