Add 18/21 and 81/30
1st number: 18/21, 2nd number: 2 21/30
18/21 + 81/30 is 249/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
18/21 = 18 × 10/21 × 10 = 180/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
81/30 = 81 × 7/30 × 7 = 567/210 - Add the two like fractions:
180/210 + 567/210 = 180 + 567/210 = 747/210 - 747/210 simplified gives 249/70
- So, 18/21 + 81/30 = 249/70
In mixed form: 339/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21+81/30 18/42+81/30 18/21+81/60 54/21+81/30 18/63+81/30 18/21+81/90 90/21+81/30