Special note: even numbers include positive even numbers, negative even numbers and 0.
0 is a special even number. Elementary school stipulated that 0 is the smallest even number, but by junior high school, I learned negative numbers. When a negative even number appears, 0 is not the smallest even number.
Question 2: What do odd and even numbers mean? Odd numbers are integers that are not divisible by 2, such as 1, 3, 5, 7, etc.
Even numbers can be divisible by 2, such as 2, 4, 6, 8, etc.
Question 3: Definition concepts of odd and even numbers Knowledge points Definition concepts of odd and even numbers
Integers can be divided into two categories: odd and even. Numbers that are divisible by 2 are called even numbers, and numbers that are not divisible by 2 are called odd numbers.
Even numbers can usually be represented by 2k (k is an integer), and odd numbers can be represented by 2k+ 1 (k is an integer).
Please note that 0 is an even number, because it is divisible by 2.
Even and odd knowledge points (5 operational properties): property 1: even = even, odd = even. Property 2: Even odd number = odd number. Property 3: Even and odd numbers add up to even numbers. Property 4: Odd numbers add up to odd numbers. Property 5: Even × odd = even, odd × odd = odd.
Question 4: What is odd and what is even integer? Numbers divisible by 2 are even, numbers divisible by 2 are odd, even numbers can be represented by 2k, and odd numbers can be represented by 2k+ 1, where k is an integer.
Special note: odd numbers include positive odd numbers and negative odd numbers.
Regarding odd and even numbers, there are the following properties:
(1) Odd numbers will not be even at the same time; Two consecutive integers must be odd and even.
(2) The sum of odd numbers and odd numbers is even; The sum of even and odd numbers is odd; The sum of any number of even numbers is even.
(3) The difference between two odd (even) numbers is even; The difference between even and odd numbers is odd numbers.
(4) If A and B are integers, the parity of a+b and a-b is the same, that is, a+b and a-b are both odd or even.
(5) The product of n odd numbers is odd, and the product of n even numbers is a multiple of 2n; If one cis is even, the product is even, that is, a * b * c *……* ... * even * x * y = even, where a, b, c, ... x, y are integers, and the formula can be simplified as: odd * even = even.
(6) Odd numbers are 0 and 5; Even numbers are 0, 2, 4, 6 and 8. 0 is a special even number. In 2002, the International Mathematical Association stipulated that zero was an even number, and in 2004, China also stipulated that zero was an even number. Elementary school stipulated that 0 is the smallest even number, but by junior high school, I learned negative numbers. When there are negative even numbers, 0 is not the smallest even number. )