Add 28/20 and 21/81
1st number: 1 8/20, 2nd number: 21/81
28/20 + 21/81 is 224/135.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 81 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 20 × 81 = 1620,
28/20 = 28 × 81/20 × 81 = 2268/1620 - Likewise, for the 2nd fraction, since 81 × 20 = 1620,
21/81 = 21 × 20/81 × 20 = 420/1620 - Add the two like fractions:
2268/1620 + 420/1620 = 2268 + 420/1620 = 2688/1620 - 2688/1620 simplified gives 224/135
- So, 28/20 + 21/81 = 224/135
In mixed form: 189/135
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/20+21/81 28/20+42/81 28/40+21/81 84/20+21/81 28/20+63/81 28/60+21/81