Add 21/56 and 18/40
21/56 + 18/40 is 33/40.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 56 and 40 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 40 × 7 = 280,
18/40 = 18 × 7/40 × 7 = 126/280 - Add the two like fractions:
105/280 + 126/280 = 105 + 126/280 = 231/280 - 231/280 simplified gives 33/40
- So, 21/56 + 18/40 = 33/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/56+18/40 21/56+36/40 21/56+18/80 63/56+18/40 21/56+54/40 21/56+90/40