Subtract 12/21 from 27/8, Solve 3 3/8

Subtract 12/21 from 27/8

1^st number: 3 3/8, 2^nd number: 12/21

27/8 - 12/21 is 157/56.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 8 × 21 = 168,
27/8 = 27 × 21/8 × 21 = 567/168
Likewise, for the 2nd fraction, since 21 × 8 = 168,
12/21 = 12 × 8/21 × 8 = 96/168
Subtract the two like fractions:
567/168 - 96/168 = 567 - 96/168 = 471/168
After reducing the fraction, the answer is 157/56
In mixed form: 245/56

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad