When calculating the division vertically, start from most significant bit, such as: 42 from most significant bit 4; 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 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.

The essence of division:

In the division calculation, the dividend is continuously divided by two divisors, which is equal to being divided by the product of these two divisors. Sometimes simple operations can be performed according to the nature of the division. For example: 300 ÷ 25 ÷ 4 = 300 ÷ (25× 4) = 300 ÷100 = 3.

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.