Add 28/40 and 90/81
1st number: 28/40, 2nd number: 1 9/81
28/40 + 90/81 is 163/90.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 81 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 40 × 81 = 3240,
28/40 = 28 × 81/40 × 81 = 2268/3240 - Likewise, for the 2nd fraction, since 81 × 40 = 3240,
90/81 = 90 × 40/81 × 40 = 3600/3240 - Add the two like fractions:
2268/3240 + 3600/3240 = 2268 + 3600/3240 = 5868/3240 - 5868/3240 simplified gives 163/90
- So, 28/40 + 90/81 = 163/90
In mixed form: 173/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/40+90/81 28/80+90/81 84/40+90/81