Add 30/81 and 21/90
30/81 + 21/90 is 163/270.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 90 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 81 × 10 = 810,
30/81 = 30 × 10/81 × 10 = 300/810 - Likewise, for the 2nd fraction, since 90 × 9 = 810,
21/90 = 21 × 9/90 × 9 = 189/810 - Add the two like fractions:
300/810 + 189/810 = 300 + 189/810 = 489/810 - 489/810 simplified gives 163/270
- So, 30/81 + 21/90 = 163/270
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/81+21/90 30/81+42/90 90/81+21/90 30/81+63/90