Add 21/18 and 72/28
1st number: 1 3/18, 2nd number: 2 16/28
21/18 + 72/28 is 157/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 28 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 18 × 14 = 252,
21/18 = 21 × 14/18 × 14 = 294/252 - Likewise, for the 2nd fraction, since 28 × 9 = 252,
72/28 = 72 × 9/28 × 9 = 648/252 - Add the two like fractions:
294/252 + 648/252 = 294 + 648/252 = 942/252 - 942/252 simplified gives 157/42
- So, 21/18 + 72/28 = 157/42
In mixed form: 331/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18+72/28 21/36+72/28 21/18+72/56 63/18+72/28 21/54+72/28 21/18+72/84 21/90+72/28