Grade 1 : Numbers

Numbers :

Numbers are the basic thing of mathematics. Numbers are used to count and to measure.

Positive Number :

A positive number is a number which is above 0. It can be written as +1, +2, +3,... or just number itself like 1, 2, 3,...

Negative Number :

A negative number is a number which is below 0. It can be written as -1, -2, -3,...

Example :

Positive and negative numbers are used  in everyday life is in measuring temperature.

If the temperature falls below 0 degree C, we can use negative numbers.

Natural Number :

The numbers which we use to count is called as Natural Number.

1, 2, 3, 4,.... are some of natural numbers

Whole Number :

Whole numbers are positive numbers including 0 without any decimal or fraction.

0, 1, 2, 3, 4,... are some of whole numbers.

NOTE : All natural number are Whole number and not vice versa because 0 is not a natural number.

Integers :

An integer is a whole number that can be positive , negative or zero.

that is, it includes

                    * counting numbers ( Natural number )

                    * Zero

                    * negative of the counting numbers (-1, -2, -3,...)

So, ...,-3, -2, -1, 0, 1, 2, 3, ...

NOTE : We can say all natural and whole numbers are integers. 

Even Number : 

Any integer that can be divided by 2 without leaving remainder. 

2, 4, 6, 8,... . Even number can also be in negative.

In simple we can say, even number is an number which we can share equally into two portions.

Odd Number :

 Any integer that cannot be divided by 2 without leaving remainder.

1, 3, 5, 7,...
Odd number can also be in negative.

In simple we can say, odd number is an number which we cannot share equally into two portions.