Number Systems

Type of numbers

• N : Natural numbers. They start from 1. [normal number]
• W: Whole numbers. They start from 0. (N and zero) [remember, hole? for zero?]
• Z: Whole numbers and negative integers. (W and -ve numbers) [remember everything so Z]
• Q: Rational numbers. They are fractions (also include Z because they can be written as W/1) [Remember q for quotient]
• How to find rational numbers between 2 integers?
• Example: between 2 and 3 find 6 rational numbers.
• Denominator is 7 (6+1). What divided by 7 gives 2 and 3?
• 2= 14/7
• 3 =21/7
• Ans: 15/7,16/7,17/7,18/7,19/7,20/7

Irrational Numbers

• Irrational if number can't be written as rational (i.e ration or fraction).
• Ex. √2