Add 70/90 and 90/81
1st number: 70/90, 2nd number: 1 9/81
70/90 + 90/81 is 17/9.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 81 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 90 × 9 = 810,
70/90 = 70 × 9/90 × 9 = 630/810 - Likewise, for the 2nd fraction, since 81 × 10 = 810,
90/81 = 90 × 10/81 × 10 = 900/810 - Add the two like fractions:
630/810 + 900/810 = 630 + 900/810 = 1530/810 - 1530/810 simplified gives 17/9
- So, 70/90 + 90/81 = 17/9
In mixed form: 18/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: