Add 21/56 and 12/20
21/56 + 12/20 is 39/40.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 56 and 20 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 56 × 5 = 280,
21/56 = 21 × 5/56 × 5 = 105/280 - Likewise, for the 2nd fraction, since 20 × 14 = 280,
12/20 = 12 × 14/20 × 14 = 168/280 - Add the two like fractions:
105/280 + 168/280 = 105 + 168/280 = 273/280 - 273/280 simplified gives 39/40
- So, 21/56 + 12/20 = 39/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/56+12/20 21/56+24/20 21/56+12/40 63/56+12/20 21/56+36/20 21/56+12/60 21/56+60/20 21/56+84/20