Subtract 1/81 from 1/20
1/20 - 1/81 is 61/1620.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 81 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 20 × 81 = 1620,
1/20 = 1 × 81/20 × 81 = 81/1620 - Likewise, for the 2nd fraction, since 81 × 20 = 1620,
1/81 = 1 × 20/81 × 20 = 20/1620 - Subtract the two like fractions:
81/1620 - 20/1620 = 81 - 20/1620 = 61/1620
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/20-1/81 1/20-2/81 1/40-1/81 3/20-1/81 1/20-3/81 1/60-1/81 5/20-1/81 1/20-5/81 7/20-1/81 1/20-7/81