Add 42/18 and 54/21
1st number: 2 6/18, 2nd number: 2 12/21
42/18 + 54/21 is 103/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
42/18 = 42 × 7/18 × 7 = 294/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
54/21 = 54 × 6/21 × 6 = 324/126 - Add the two like fractions:
294/126 + 324/126 = 294 + 324/126 = 618/126 - 618/126 simplified gives 103/21
- So, 42/18 + 54/21 = 103/21
In mixed form: 419/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/18+54/21 42/36+54/21 42/18+54/42 42/54+54/21 42/18+54/63 42/90+54/21