Subtract 20/81 from 5/8
5/8 - 20/81 is 245/648.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 81 is 648
Next, find the equivalent fraction of both fractional numbers with denominator 648 - For the 1st fraction, since 8 × 81 = 648,
5/8 = 5 × 81/8 × 81 = 405/648 - Likewise, for the 2nd fraction, since 81 × 8 = 648,
20/81 = 20 × 8/81 × 8 = 160/648 - Subtract the two like fractions:
405/648 - 160/648 = 405 - 160/648 = 245/648
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/8-20/81 5/8-40/81 5/16-20/81 15/8-20/81 5/8-60/81 5/24-20/81 25/8-20/81 5/40-20/81 35/8-20/81 5/56-20/81