Add 1/20 and 7/21
1/20 + 7/21 is 23/60.
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,
1/20 = 1 × 21/20 × 21 = 21/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
7/21 = 7 × 20/21 × 20 = 140/420 - Add the two like fractions:
21/420 + 140/420 = 21 + 140/420 = 161/420 - 161/420 simplified gives 23/60
- So, 1/20 + 7/21 = 23/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/20+7/21 1/20+14/21 1/40+7/21 1/20+7/42 3/20+7/21 1/60+7/21 1/20+7/63 5/20+7/21 1/20+35/21 7/20+7/21 1/20+49/21