Add 81/21 and 81/60
1st number: 3 18/21, 2nd number: 1 21/60
81/21 + 81/60 is 729/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 60 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
81/21 = 81 × 20/21 × 20 = 1620/420 - Likewise, for the 2nd fraction, since 60 × 7 = 420,
81/60 = 81 × 7/60 × 7 = 567/420 - Add the two like fractions:
1620/420 + 567/420 = 1620 + 567/420 = 2187/420 - 2187/420 simplified gives 729/140
- So, 81/21 + 81/60 = 729/140
In mixed form: 529/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/42+81/60 81/63+81/60