Add 72/21 and 54/18
1st number: 3 9/21, 2nd number: 3 0/18
72/21 + 54/18 is 45/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
72/21 = 72 × 6/21 × 6 = 432/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
54/18 = 54 × 7/18 × 7 = 378/126 - Add the two like fractions:
432/126 + 378/126 = 432 + 378/126 = 810/126 - 810/126 simplified gives 45/7
- So, 72/21 + 54/18 = 45/7
In mixed form: 63/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/42+54/18 72/21+54/36 72/63+54/18 72/21+54/90