Subtract 21/20 from 18/10
1st number: 1 8/10, 2nd number: 1 1/20
18/10 - 21/20 is 3/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 10 and 20 is 20
Next, find the equivalent fraction of both fractional numbers with denominator 20 - For the 1st fraction, since 10 × 2 = 20,
18/10 = 18 × 2/10 × 2 = 36/20 - Likewise, for the 2nd fraction, since 20 × 1 = 20,
21/20 = 21 × 1/20 × 1 = 21/20 - Subtract the two like fractions:
36/20 - 21/20 = 36 - 21/20 = 15/20 - After reducing the fraction, the answer is 3/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/10-21/20 18/10-42/20 18/20-21/20 18/10-21/40 54/10-21/20 18/10-63/20 18/30-21/20 18/10-21/60 90/10-21/20 18/50-21/20 18/70-21/20