Add 72/21 and 81/18
1st number: 3 9/21, 2nd number: 4 9/18
72/21 + 81/18 is 111/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
72/21 = 72 × 6/21 × 6 = 432/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
81/18 = 81 × 7/18 × 7 = 567/126 - Add the two like fractions:
432/126 + 567/126 = 432 + 567/126 = 999/126 - 999/126 simplified gives 111/14
- So, 72/21 + 81/18 = 111/14
In mixed form: 713/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/42+81/18 72/21+81/36 72/63+81/18 72/21+81/54 72/21+81/90