Add 3/18 and 54/21
1st number: 3/18, 2nd number: 2 12/21
3/18 + 54/21 is 115/42.
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,
3/18 = 3 × 7/18 × 7 = 21/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
54/21 = 54 × 6/21 × 6 = 324/126 - Add the two like fractions:
21/126 + 324/126 = 21 + 324/126 = 345/126 - 345/126 simplified gives 115/42
- So, 3/18 + 54/21 = 115/42
In mixed form: 231/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/18+54/21 3/36+54/21 3/18+54/42 9/18+54/21 3/54+54/21 3/18+54/63 15/18+54/21 3/90+54/21 21/18+54/21