If a number is a multiple of 2, it is even and can be expressed as 2n; Otherwise, it is an odd number, which can be expressed as 2n+ 1(n is an integer), that is, the remainder of odd number divided by two is 1.
1, even number is a definition of logarithm in mathematics. All integers divisible by two digits are called even numbers. Because the number 0 is divided by any number, it is also recognized as the most special even number, and even number is also called "even number" in our daily oral expression.
2. Even numbers are mainly divided into two types, one is a positive even number greater than 0, and the other is a negative even number less than 0.
In mathematics study or research, we often use 2n to refer to any even number. It is particularly important to note that n in 2n refers to any integer including 0.
3. The number opposite to even number is odd number. Like even numbers, there are positive odd numbers and negative odd numbers. In mathematics study or research, we often use 2n+ 1 to refer to any even number.
Similarly, when n refers to any integer including 0, there are still some wonderful relationships between even and odd numbers. For example, the sum of odd numbers of two people must be even.
All integers are either odd or even. If a number is a multiple of 2, it is even and can be expressed as 2n; Otherwise, it is an odd number, which can be expressed as 2n+ 1(n is an integer), that is, the remainder of odd number divided by two is 1.
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 (singular); Numbers with digits 0, 2, 4, 6 and 8 are even (even).
The meaning of integer
Integers are numbers like 0, 1, 2, 3,-10, 1 3, 10, etc. All integers form an integer set, which is a number ring. In the integer system, zero and positive integers are collectively called natural numbers. -1, -2, -3, …, -n, …(n is a non-zero natural number) are negative integers. Positive integers, zero integers and negative integers form an integer system. Integers exclude decimals and fractions.