Subtract 1/21 from 9/10
9/10 - 1/21 is 179/210.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 10 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 10 × 21 = 210,
9/10 = 9 × 21/10 × 21 = 189/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
1/21 = 1 × 10/21 × 10 = 10/210 - Subtract the two like fractions:
189/210 - 10/210 = 189 - 10/210 = 179/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/10-1/21 9/10-2/21 9/20-1/21 9/10-1/42 27/10-1/21 9/10-3/21 9/30-1/21 9/10-1/63 45/10-1/21 9/10-5/21 9/50-1/21 63/10-1/21 9/10-7/21 9/70-1/21