Add 20/30 and 81/7
1st number: 20/30, 2nd number: 11 4/7
20/30 + 81/7 is 257/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 7 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
20/30 = 20 × 7/30 × 7 = 140/210 - Likewise, for the 2nd fraction, since 7 × 30 = 210,
81/7 = 81 × 30/7 × 30 = 2430/210 - Add the two like fractions:
140/210 + 2430/210 = 140 + 2430/210 = 2570/210 - 2570/210 simplified gives 257/21
- So, 20/30 + 81/7 = 257/21
In mixed form: 125/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/30+81/7 20/60+81/7 20/30+81/14 60/30+81/7 20/90+81/7 20/30+81/21 20/30+81/35 20/30+81/49