Subtract 1/21 from 1/6
1/6 - 1/21 is 5/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 6 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 6 × 7 = 42,
1/6 = 1 × 7/6 × 7 = 7/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
1/21 = 1 × 2/21 × 2 = 2/42 - Subtract the two like fractions:
7/42 - 2/42 = 7 - 2/42 = 5/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/6-1/21 1/6-2/21 1/12-1/21 1/6-1/42 3/6-1/21 1/6-3/21 1/18-1/21 1/6-1/63 5/6-1/21 1/6-5/21 1/30-1/21 7/6-1/21 1/6-7/21 1/42-1/21