A.25 and 2

B.3 and 12

C.4 and 0.5

D.5 1 and 17

In mathematical division calculation, the final result of 5 1÷ 17 is 3, the divisor (not 0) and the quotient are integers, and there is no remainder, so it can be said that the first number can be divisible by the second number. Knowing the product of two factors and one of them, the operation of finding the other factor is called division.

The division of integers is introduced as follows:

Starting from the high order of the dividend, first look at how many digits there are in the dividend, and then try to divide the first few digits of the dividend by the divisor. If it is less than the dividend, try dividing it by one digit. Write the quotient on it except the dividend; The remainder after each division operation must be less than the divisor.

The multiplication rule of integers is one of the arithmetic rules of integers, and the multiplication rule of integers is manifested in three situations. Multiply two numbers, the same sign is positive, the different sign is negative, and then multiply by the absolute value.

In integer division, the divisor must be less than the dividend. When the dividend does not exceed two digits, the divisor is one digit, and the quotient is also one digit, the quotient and the remainder (the remainder may be zero) can be directly obtained according to the multiplication formula, which is called division in the table. Division in which the dividend exceeds two digits is called multi-digit division.

The multiplication rule of integers is one of the arithmetic rules of integers. The multiplication rule of integers is manifested in three situations:

1. One-digit multiplication rule. The product of two one-digit numbers can be calculated by addition according to the definition of multiplication. Usually, the product of any two one-digit numbers can be directly obtained by using the multiplication table.

2. Multi-digit multiplication rule. Multiply the number on each bit of the multiplicand by the number on each bit of the multiplier in turn, and then add the products.

Extended data:

In integer division, the divisor must be less than the dividend. When the dividend does not exceed two digits, the divisor is one digit, and the quotient is also one digit, the quotient and the remainder (the remainder may be zero) can be directly obtained according to the multiplication formula, which is called division in the table. Division in which the dividend exceeds two digits is called multi-digit division.

Zero and positive integers are collectively called natural numbers. Integers can also be divided into odd and even numbers. An integer divisible by 2 is called an even number. Numbers that are not divisible by 2 are called odd numbers. That is, when n is an integer, even numbers can be expressed as 2n(n is an integer); Odd numbers can be expressed as 2n+ 1 (or 2n- 1).

Even numbers include positive even numbers (also called even numbers), negative even numbers and 0. All integers are either odd or even. In decimal system, we can judge whether the number is odd or even by looking at the single digits: 1, 3, 5, 7 and 9 are odd; Numbers with digits 0, 2, 4, 6 and 8 are even numbers.