Add 18/72 and 24/21
1st number: 18/72, 2nd number: 1 3/21
18/72 + 24/21 is 39/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 21 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 72 × 7 = 504,
18/72 = 18 × 7/72 × 7 = 126/504 - Likewise, for the 2nd fraction, since 21 × 24 = 504,
24/21 = 24 × 24/21 × 24 = 576/504 - Add the two like fractions:
126/504 + 576/504 = 126 + 576/504 = 702/504 - 702/504 simplified gives 39/28
- So, 18/72 + 24/21 = 39/28
In mixed form: 111/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/72+24/21 18/72+48/21 18/72+24/42 54/72+24/21 18/72+72/21 18/72+24/63 90/72+24/21