Take "minus nine plus one" as an example. "Minus nine plus one" refers to a number MINUS nine, and the result of adding 1 to the unit of this number is their difference.
Subtraction of abdication means that when two numbers are subtracted and the number of digits to be subtracted is not enough, borrowing the previous digit is equivalent to adding 10 to this digit and then calculating.
Subtraction follows several important patterns. It is anti-commutative, which means that changing the order will change the sign of the answer. It is not associative law, that is, when a subtraction exceeds two numbers, the order of subtraction is very important. Subtracting 0 does not change a number.
Abdication subtraction
1, abdication subtraction should be kept in mind, starting from the unit.
2, who is not enough to return, don't forget to add ten to the standard.
3. If the interval is 1, it is best to remember that 0 changes to 10.
Successive abdication subtraction
1, see 0, go ahead and see which one has it.
2. borrow it back. 0 is a bit like 9.