What is vertical division?

Divide by the highest digit, such as: 42, divide by 4 from the highest digit; If it can't be divisible, for example, 4 can't be divisible by 7, then use the highest bit and the next bit to synthesize a number to be divisible until it can be divisible by the divisor.

For example, if 42 is divided by 7, 4 can't divide 7. Just combine 4 and 2 into a number. If 42 is divided by 7, the quotient is 6.

The significance of vertical calculation:

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.

Each transition number is changed by the last transition number, and then the single digits of the last transition number are multiplied by 2. If carry is needed, advance 1, then increase the unit number by ten digits, and so on, and add the new operand to the unit number.