Page 56 - Revised Maths Wisdom Class - 6

4 Number Play

CHAPTER OUTLINES

● Classification of Things by Using Numbers ● Playing With Digits ● Kaprekar Constant
● Super Cells ● Digit Sum of Numbers ● The Collatz Conjecture
● Patterns of Numbers in the Number Line ● Palindromic Numbers ● Estimation

RECALL

● Natural number ‘1’ has no predecessor.
● 1 is the smallest natural number.
● Numbers having one digit i.e., 1 to 9 (Total numbers = 9)
● Numbers having two digits i.e., 10, 11, 12... 99 (Total numbers = 90)
● Numbers having three digits i.e., 100, 101, ... 999 (Total numbers = 900)
● Numbers having four digits i.e., 1000, 1001, 1002 ... 9999 (Total numbers = 9000)
● Numbers having five digits i.e., 10000, 10001, 10002, ... 99999 (Total numbers = 90,000)
● Always, sometimes, never
(i) 5-digit number + 5 digit number = either 5 or 6 digit number
(ii) 4-digit number + 2 digit number = either 4 or 5 digit number
(iii) 5-digit number + 5 digit number = may be 0/1/2/3/4/5 digit number

Introduction

Number is a basic component of Mathematics. Numbers are used in different-different ways to organise our work,
our lives etc. Numbers are used for counting, measuring, keeping things in order, indexing and many more by
applying the basic operations like addition, subtraction, multiplication and division on them.

With the help of this chapter, we will carry on this journey by playing with numbers, by seeing numbers around
us, seeing patterns and to use the operations in new ways.

Classification of Things by using Numbers
Classification can be defined as the arrangement or sorting of objects into groups on the basis of a common
property that all of them have. It refers to the process of categorizing objects or numbers into distinct groups or
classes based on their characteristics.
We can classify numbers or figures on the basis of various parameters depending on the object we are dealing with.

Let’s discuss a few ways to understand this
(i) Classification of objects by their height (a number)

We can classify people based on their height.