Explanation:
All numbers belong to the set of numbers known as the real number system. The real number system consists of
every number you have ever dealt with since you were old enough to count. The numbers in the real number system
are divided into two main groups. One group is called the rational numbers and the other is called the irrational
numbers. The set of irrational numbers consists of all numbers that are not rational. This set of irrational numbers
includes those numbers that cannot be written as the ratio of two integers, non-remediate numbers.
and decimals that do not have a repeating pattern of digits. For example, pi(π),
√
2,−2.345876921... are irrational
numbers.
The set of rational numbers includes natural numbers, whole numbers, integers, numbers that can be expressed as
the ratio of two integers, a decimal number that terminates, and decimal numbers that have a repeating pattern of digits.
The natural numbers are the set of positive integers. For example, 1, 2, 3. . . are all natural numbers. The whole
numbers are the natural numbers and zero. For example, 0, 1, 2, 3. . . are all whole numbers. The integers are
the whole numbers and their opposites. For example, -2, -1, 0, 1, 2. . . are all integers. A rational number is any
number that can be expressed in the form of a
b where b 6= 0. When a rational number is expressed as a decimal, it
decimal will terminate (end) or For example, 1
2
,
√
81,−7.456 545 654 are
all rational numbers.
When you classify numbers remember that they can often belong to more than one set of numbers. If you think of
the number 3, you can call it a natural number, a whole number, an integer and a rational number.
The following table may help you to better understand the real number system.