Add 81/30 and 28/21
1st number: 2 21/30, 2nd number: 1 7/21
81/30 + 28/21 is 121/30.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
81/30 = 81 × 7/30 × 7 = 567/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
28/21 = 28 × 10/21 × 10 = 280/210 - Add the two like fractions:
567/210 + 280/210 = 567 + 280/210 = 847/210 - 847/210 simplified gives 121/30
- So, 81/30 + 28/21 = 121/30
In mixed form: 41/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/30+56/21 81/60+28/21 81/30+28/42 81/30+84/21 81/90+28/21 81/30+28/63