In order to simplify the calculation, a vertical calculation is listed. In addition calculation, the same numbers are aligned. If the sum exceeds 10, it will move forward to 1. When subtracting, the same numbers are aligned. If it is not enough, borrow 1 from the last digit as 10. ?

Division calculation:

When the dividend is not 0 (for example, 3÷0), because "any number multiplied by 0 is equal to 0, but it cannot be equal to a number that is not 0 (for example, 3)", the quotient of the division formula does not exist at this time-that is, 0 times of any number cannot be non-zero.

When the dividend is 0, that is, the division formula is 0÷0, because "any number multiplied by 0 equals 0", the quotient can be any number-that is, 0 times of any number equals 0.