Add 21/60 and 35/70
21/60 + 35/70 is 17/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 60 and 70 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 70 × 6 = 420,
35/70 = 35 × 6/70 × 6 = 210/420 - Add the two like fractions:
147/420 + 210/420 = 147 + 210/420 = 357/420 - 357/420 simplified gives 17/20
- So, 21/60 + 35/70 = 17/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/60+35/70 63/60+35/70