1. 2 1 ÷ 5 = 4... 1.

2.32 ÷ 6 = 5 ...2.

In integer division, there are only two situations: divisible and irredivisible. The remainder is generated when it is not divisible, so the remainder problem is very important in primary school mathematics. When it is not divisible, it will produce a remainder. Take the remainder operation: a mod b = c(b is not 0) means that the remainder obtained by dividing integer a by integer b is c, for example, 7 ÷ 3 = 2. ...

Law of division:

The purpose of division is to find the quotient, but when you suddenly can't see how many quotients are contained in the dividend, you can use the method of trial quotient and estimated quotient to see how many divisors are contained in the highest digit of the multiplicand (that is, how many times the quotient is contained), and then add several times the complement from the standard number to get the quotient.

Small array: When the dividend contains divisor 1, 2 or 3 times, the method is as follows:

Dividend includes quotient 1 multiple: the complement is added once from the standard.

Dividends include two quotients: from standard to supplementary.

Dividends include three quotients: from standard to supplementary three times.