Add 42/28 and 21/40
1st number: 1 14/28, 2nd number: 21/40
42/28 + 21/40 is 81/40.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 40 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 28 × 10 = 280,
42/28 = 42 × 10/28 × 10 = 420/280 - Likewise, for the 2nd fraction, since 40 × 7 = 280,
21/40 = 21 × 7/40 × 7 = 147/280 - Add the two like fractions:
420/280 + 147/280 = 420 + 147/280 = 567/280 - 567/280 simplified gives 81/40
- So, 42/28 + 21/40 = 81/40
In mixed form: 21/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/28+21/40 42/28+42/40 42/56+21/40 42/28+21/80 42/28+63/40 42/84+21/40