All numbers that cannot be divided exactly by 2 are odd numbers.
Odd numbers can't be divided evenly into groups of two. The number five can be divided into two groups of two and one group of one. Odd numbers always end with a digit of 1, 3, 5, 7, or 9.
About Number 3. Three is the first odd prime number and the second smallest right after number two. At the same time it is the first Mersenne prime (2 ^ 2-1), the first Fermat prime (2 ^ {2 ^ 0} +1), the second Sophie Germain prime and the second Mersenne prime exponent. It is the fourth number of the Fibonacci sequence and the second one that is unique. The triangle is the simplest geometric figure in the plane. With the calculation of its sizes deals trigonometry. Rule of three: If the sum of the digits of a number is a multiple of three, the underlying number is divisible by three.
About Number 0. The number zero is the number of elements in an empty collection of objects, mathematically speaking, the cardinality of the empty set. Zero in mathematics by depending on the context variously defined objects, but often can be identified with each other, that is considered to be the same object, which combines several properties compatible with each other. As cardinal numbers (number of elements in a set) are identified with special ordinals, and the zero is just the smallest cardinal number is zero - elected as the first ordinal - in contrast to common parlance. As finite cardinal and ordinal it is depending on the definition often counted among the natural numbers. The zero is the identity element for addition in many bodies, such as the rational numbers, real numbers and complex numbers, and a common name for a neutral element in many algebraic structures, even if other elements are not identified with common numbers. Zero is the only real number that is neither positive nor negative.
What Is An Odd Number?
An odd number is an integer which is not a multiple of two. If it is divided by two the result is a fraction. One is the first odd positive number. The next four bigger odd numbers are three, five, seven, and nine. An integer that is not an odd number is an even number.
An even number is defined as a whole number that is a multiple of two. If an even number is divided by two, the result is another whole number. On the other hand, an odd number, when divided by two, will result in a fraction. Since odd and even numbers are defined only in reference to the set of integers (..., -3, -2, -1, 0, 1, 2, 3, ...), all negative numbers can also be either odd or even.