Add 10/20 and 3/21
10/20 + 3/21 is 9/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
10/20 = 10 × 21/20 × 21 = 210/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
3/21 = 3 × 20/21 × 20 = 60/420 - Add the two like fractions:
210/420 + 60/420 = 210 + 60/420 = 270/420 - 270/420 simplified gives 9/14
- So, 10/20 + 3/21 = 9/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/20+6/21 10/40+3/21 10/20+3/42 30/20+3/21 10/20+9/21 10/60+3/21 10/20+3/63 50/20+3/21 10/20+15/21 70/20+3/21