Add 81/21 and 81/54
1st number: 3 18/21, 2nd number: 1 27/54
81/21 + 81/54 is 75/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 21 × 18 = 378,
81/21 = 81 × 18/21 × 18 = 1458/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
81/54 = 81 × 7/54 × 7 = 567/378 - Add the two like fractions:
1458/378 + 567/378 = 1458 + 567/378 = 2025/378 - 2025/378 simplified gives 75/14
- So, 81/21 + 81/54 = 75/14
In mixed form: 55/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/42+81/54 81/63+81/54