The principle is the same as in addition. Reduce the fractions, if they have different denominators, to a common denominator, and then take the difference of the numerators. In the case of mixed numbers, subtract the whole numbers and the fractions separately.
Example 1: Take 45⁄21 from 63⁄7.
637 - 4521 = 6 - 4 + 37 - 521
637 - 4521 = 2 + 9 - 521
637 - 4521 = 2 + 421 = 2421 Ans.
If the fractional part of the number to be subtracted be greater than the fractional part of the other number, we proceed as follows:
Example 2: From 74⁄15 take 411⁄25.
7415 - 41125 = 7 - 4 + 415 - 1125
7415 - 41125 = 3 + 20 - 3375
7415 - 41125 = 2 + 75 + 20 - 3375