Add 30/9 and 81/21
1st number: 3 3/9, 2nd number: 3 18/21
30/9 + 81/21 is 151/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 21 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
30/9 = 30 × 7/9 × 7 = 210/63 - Likewise, for the 2nd fraction, since 21 × 3 = 63,
81/21 = 81 × 3/21 × 3 = 243/63 - Add the two like fractions:
210/63 + 243/63 = 210 + 243/63 = 453/63 - 453/63 simplified gives 151/21
- So, 30/9 + 81/21 = 151/21
In mixed form: 74/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/9+81/21 30/18+81/21 30/9+81/42 90/9+81/21 30/27+81/21 30/9+81/63 30/45+81/21 30/63+81/21