Add 18/21 and 6/20
18/21 + 6/20 is 81/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
18/21 = 18 × 20/21 × 20 = 360/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
6/20 = 6 × 21/20 × 21 = 126/420 - Add the two like fractions:
360/420 + 126/420 = 360 + 126/420 = 486/420 - 486/420 simplified gives 81/70
- So, 18/21 + 6/20 = 81/70
In mixed form: 111/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+6/20 18/21+12/20 18/42+6/20 18/21+6/40 54/21+6/20 18/21+18/20 18/63+6/20 18/21+6/60 90/21+6/20 18/21+30/20 18/21+42/20