The same numbers are aligned. If the sum exceeds 10, it will move forward to 1. For example:

435

+697

———

1 132

Step 2 subtract

If the same number is aligned, borrow 1 from the previous number as 10 if it is not reduced enough. For example:

756

-569

————

187

Extended data:

1, multiplication

The i-th bit of one number is multiplied by the j-th bit of another number.

It should be added to i+j- 1 bit of the product.

Step 2 separate

For example, 42 divided 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.

Baidu Encyclopedia-Vertical Computing