Subtract 18/8 from 81/90
1st number: 81/90, 2nd number: 2 2/8
81/90 - 18/8 is -27/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 8 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 90 × 4 = 360,
81/90 = 81 × 4/90 × 4 = 324/360 - Likewise, for the 2nd fraction, since 8 × 45 = 360,
18/8 = 18 × 45/8 × 45 = 810/360 - Subtract the two like fractions:
324/360 - 810/360 = 324 - 810/360 = -486/360 - After reducing the fraction, the answer is -27/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/90-36/8 81/90-18/16 81/90-54/8 81/90-18/24 81/90-90/8 81/90-18/40 81/90-18/56