Add 20/4 and 81/21
1st number: 5 0/4, 2nd number: 3 18/21
20/4 + 81/21 is 62/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 4 × 21 = 84,
20/4 = 20 × 21/4 × 21 = 420/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
81/21 = 81 × 4/21 × 4 = 324/84 - Add the two like fractions:
420/84 + 324/84 = 420 + 324/84 = 744/84 - 744/84 simplified gives 62/7
- So, 20/4 + 81/21 = 62/7
In mixed form: 86/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/4+81/21 20/8+81/21 20/4+81/42 60/4+81/21 20/12+81/21 20/4+81/63 20/28+81/21