Add 30/42 and 81/21
1st number: 30/42, 2nd number: 3 18/21
30/42 + 81/21 is 32/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
30/42 = 30 × 1/42 × 1 = 30/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
81/21 = 81 × 2/21 × 2 = 162/42 - Add the two like fractions:
30/42 + 162/42 = 30 + 162/42 = 192/42 - 192/42 simplified gives 32/7
- So, 30/42 + 81/21 = 32/7
In mixed form: 44/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/42+81/21 30/84+81/21 30/42+81/42 90/42+81/21 30/42+81/63