Add 81/28 and 15/90
1st number: 2 25/28, 2nd number: 15/90
81/28 + 15/90 is 257/84.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 90 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 28 × 45 = 1260,
81/28 = 81 × 45/28 × 45 = 3645/1260 - Likewise, for the 2nd fraction, since 90 × 14 = 1260,
15/90 = 15 × 14/90 × 14 = 210/1260 - Add the two like fractions:
3645/1260 + 210/1260 = 3645 + 210/1260 = 3855/1260 - 3855/1260 simplified gives 257/84
- So, 81/28 + 15/90 = 257/84
In mixed form: 35/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/28+30/90 81/56+15/90 81/28+45/90 81/84+15/90 81/28+75/90