The abdication subtraction is a simple subtraction method, which is suitable for the subtraction of two integers, in which the minuend is smaller than the corresponding minuend. The basic idea is to borrow the low bit of the minuend from the high bit, so that one bit of the minuend is greater than or equal to the corresponding bit of the minuend, and then subtract the two numbers.

The specific steps of abdication subtraction are as follows: starting from the minuend, if the minuend is less than the minuend, borrow from the high position, and the number of low positions will be reduced by 1 after borrowing. Subtract the minuend bit from the minuend bit to get the difference, and write the difference on the corresponding bit.

Repeat the above steps until all bits have been calculated. It should be noted that if a bit of the minuend is already 0 in the borrowing process, it needs to continue to borrow from a higher bit until it encounters a bit that is not 0.

For example, the calculation of 3247- 1879 starts from one unit. If 4 is less than 9, it needs to be borrowed from ten units. After borrowing, 2 minus 1 equals 1, so the difference of one unit is 8. Then if the 4 in the tenth place is less than 7, you must borrow it from the hundred. After borrowing, 2 minus 1 equals 1, so the difference in the tenth digit is 2.

2 in the hundreds is greater than or equal to 8, and the difference of 4 is directly subtracted. Three thousandths is greater than or equal to 1, and the direct subtraction difference is 2. So 3247- 1879 = 1368. The abdication subtraction is simple and easy to understand, which can help us to do subtraction quickly, especially in the scene of paper-and-pencil calculation, which is more convenient and practical.

In addition to the common vertical subtraction and abdication subtraction, there are some other subtraction methods, including: borrowing subtraction: this method is suitable for the case that the reduced bit is less than the corresponding bit. The specific steps are as follows: starting from the minuend, if the minuend is less than the minuend, borrow from the high position, and the low digit after borrowing will be reduced by 1.

Then subtract the minuend from the minuend to get a difference, and write the difference on the corresponding bit. Repeat the above steps until all bits have been calculated.

For example, to calculate 37 1- 168, you can use borrowing subtraction: starting from single digits, 1 less than 8, you need to borrow from ten digits. After borrowing, the original 7 becomes 6, so the difference between each number is 3.

Then the tenth 7 is also less than 8, so you need to borrow it from hundreds. After borrowing, the original 3 became 2, so the difference in the tenth place was 0. The last three percent is greater than or equal to 1, and the difference of 2 is directly subtracted. Therefore, 37 1- 168 = 203.