**Solution:**When we subtract numbers, we arrange them one under the other like in the image. We subtract the digits in the same column from right to left. If the first digit in the column is smaller than the second, we'll form a two-digit number in which the tens digit is 1 subtracted from the next column (the one to the left) and the unit digits is the first digit in the column in which we do the subtraction. When subtracting the digits from the next column, we remember that we subtracted 1 from it.
7963 - 4728 = 3235