Number Systems
CBSE Class 9 Maths
Important Points To Remember
① Counting numbers 1, 2, 3, 4... are called Natural Numbers (N)
② Whole Numbers (W): Natural numbers 1, 2, 3... together with number 0 (zero) are called Whole Numbers
③ All natural numbers, zero and negative numbers together i.e. ...., –4, –3, –2, –1, 0, 1, 2, 3, 4, ... are known as Integers (Z).
④ Rational Numbers (Q): Numbers of the form p/q where p, q both are integers and q ≠ 0.