## Friday, 13 January 2017

### An Introduction: The Number Family

Before we start discussing the different types of numbers, we learn the different types of numbers, and their relationship. We will discuss further when we work on Unit 02.

The relationship between the numbers system is as follows:

Amongst the 4 types of numbers:
• NATURAL NUMBERS is the smallest of all - starts from 1, followed by 2, 3, 4, 5, ... basically, it's positive integers
• INTEGERS is made up by negative integers (-1, -2, -3, .... ), zero (0) and positive integers (1, 2, 3, ...)
• RATIONAL NUMBERS are numbers that can be expressed as a fraction a/b such that both a and b are integers and b is non-zero. Integers and natural numbers are rational numbers since we can express them with denominator = 1.
• REAL NUMBERS are numbers include natural numbers, integers and rational numbers. It also includes numbers that cannot be expressed as a fraction, e.g. pi, square root of 2
Note: Whole numbers and Complex numbers are not mentioned above.

Attempt the following exercise to check your understanding