Add 90/72 and 20/81
1st number: 1 18/72, 2nd number: 20/81
90/72 + 20/81 is 485/324.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 81 is 648
Next, find the equivalent fraction of both fractional numbers with denominator 648 - For the 1st fraction, since 72 × 9 = 648,
90/72 = 90 × 9/72 × 9 = 810/648 - Likewise, for the 2nd fraction, since 81 × 8 = 648,
20/81 = 20 × 8/81 × 8 = 160/648 - Add the two like fractions:
810/648 + 160/648 = 810 + 160/648 = 970/648 - 970/648 simplified gives 485/324
- So, 90/72 + 20/81 = 485/324
In mixed form: 1161/324
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/72+40/81 90/72+60/81