Whole Numbers

Summary

LearnNext Lesson Video

Natural numbers
The numbers used for counting are called natural numbers. Every natural number is a whole number.

Predecessor and Successor
The number that comes immediately before another number in counting is called its predecessor. The number that comes immediately after another number in counting is called its successor.

To find the successor of a whole number, just add 1 to the given number. Similarly, to find the predecessor of a whole number, subtract 1 from the given number.
The value of nothing is represented by the number zero. Zero is not the successor of any whole number.
e.g. 3 – 3 = 0.

Whole numbers
Natural numbers together with the number zero are called whole numbers. Zero is the smallest whole number. There is no largest whole number.

Whole numbers can be represented on the number line. There are no numbers to the left of zero on the number line. When comparing two whole numbers, the number that lies to the right on the number line is greater. When comparing two whole numbers, the number that lies to the left on the number line is smaller.

Whole numbers can be added, subtracted and multiplied on the number line.

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1 . FIND THE GREATEST NUMBER OF FIVE DIGITS THAT IS EXACTLY DICISIBLE BY 9, 12, 15, 18 AND 24?

Sol:
LCM of 9, 12, 15, 18 and 24 by division method is 360.
Largest number of five digits = 99999
The quotient when...

2 . The traffic lights at three different road crossing change

Here we have to find LCM of 72, 108 and 132
LCM of 72, 108, 132 = 2376
To convert 2376 sec into min, we get
So the...

3 . The HCF & LCM of two numbers are 13 and 1989 respectively.

hcfXlcm=aXb
hcf=13,lcm=1989, a=17
b=(13*1989)/17
b=221
other number is 221

4 . Sample paper SA 1

SA 1 sample papers:

How many centimetres are there in 5 kilometres?
How many centimetres are there in 5 kilometres?...

5 . Sample question paper for SA1

Please go through the SA 1 sample question papers from the following link:
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