Add 21/84 and 1/20
21/84 + 1/20 is 3/10.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
21/84 = 21 × 5/84 × 5 = 105/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
1/20 = 1 × 21/20 × 21 = 21/420 - Add the two like fractions:
105/420 + 21/420 = 105 + 21/420 = 126/420 - 126/420 simplified gives 3/10
- So, 21/84 + 1/20 = 3/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84+1/20 21/84+2/20 21/84+1/40 63/84+1/20 21/84+3/20 21/84+1/60 21/84+5/20 21/84+7/20