Vertical calculation refers to a vertical calculation in the calculation process, which makes the calculation simple.
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.
The I-th bit of one number multiplied by the J-th bit of another number should be added to i+j- 1 bit of the product and divided by 42, for example, by 7. On a scale of 4 [from high to low].
When calculating the division vertically, start from most significant bit, such as: 42 from most significant bit 4; If it is not divisible, such as: 4 is not 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 4 is not divisible by 7 in 42, then 4 and 2 are combined into a number. If 42 is divided by 7, the quotient is 6.