Add 21/60 and 15/21
21/60 + 15/21 is 149/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 60 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 60 × 7 = 420,
21/60 = 21 × 7/60 × 7 = 147/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
15/21 = 15 × 20/21 × 20 = 300/420 - Add the two like fractions:
147/420 + 300/420 = 147 + 300/420 = 447/420 - 447/420 simplified gives 149/140
- So, 21/60 + 15/21 = 149/140
In mixed form: 19/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/60+15/21 21/60+30/21 21/60+15/42 63/60+15/21 21/60+45/21 21/60+15/63 21/60+75/21