Subtract one from the whole number of the minuend. For example, if the problem is 7 (2 / 4) - 5 (3 / 4) = , then subtract 1 from 7. This gives you 7 - 1 = 6.
Add one to the fraction of the minuend. When borrowing, what is taken from one part of the minuend is added to the other. One is equivalent to the same numerator and denominator. Since 4 is in the denominator 1 = 4 / 4. For example, 4 / 4 + 2 / 4 = 6 / 4. This gives you a final answer of 6 (6 / 4) - 5 (3 / 4) = .
Subtract the whole numbers and subtract the numerators. After you borrow, you can proceed with the subtraction problem as normal. For example, 6 (6 / 4) - 5 (3 / 4) = 1 (3 / 4).