Numbers which are used to count things are 
known as NATURAL NUMBERS.
Eg. 1,2,3,4…………………………….
NEGETIVE NUMBERS 
-1,-2,-3,-4……………………………… 
This type of numbers , 
which having a negative sign 
are known as NEGATIVE NUMBERS
RATIONAL NUMBERS 
NATURAL NUMBERS 
NEGATIVE NUMBERS 
ZERO, FRACTIONS AND 
THEIR NEGATIVES collectively known as 
RATIONAL NUMBERS
IRRATIONAL NUMBERS 
The numbers which are 
not rational are 
IRRATIONALS
IRRATIONAL NUMBERS 
Eg. √2, √3, √5, Π…………….
REAL NUMBERS 
The numbers 
RATIONALS and IRRATIONALS 
Together known as REAL NUMBERS
NUMBER LINE
LINE WHICH CONTAINS ALL 
REAL NUMBERS AS POINTS.
. . . . . . . . . . . . . . . . . . . -9-8-7 -6-5-4 -3 -2-1 0 1 2 3 4 5 6 7 8 9
RATIONAL NUMBERS 
ON NUMBER LINE
. . . . . . . . . . . . . . . . . . . -4 -3 -2 -1 0 1/2 1 2 3 4 -3/2
IRRATIONAL NUMBERS 
ON NUMBER LINE
-9-8-7 -6-5-4 -3 -2-1 √2 1 2 3 4 5 6 7 8 9 
. . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . -9-8-7 -6-5-4 -3 -2-1 1 2 3 4 5 6 7 8 9 
.Π 
0
SMALL AND LARGE 
LEFT AND RIGHT
WHEN WE GOES THROUGH RIGHT 
SIDE OF A NUMBER LINE THE VALUE 
OF THE POINTS ARE INCREASES.
WHEN WE GOES THROUGH LEFT SIDE 
OF A NUMBER LINE THE VALUE OF THE 
POINTS ARE DECREASES.
. . . . . . . . . . . . . . . . . . . -9-8-7 -6-5-4 -3 -2-1 0 1 2 3 4 5 6 7 8 9 
2<x<4
. . . . . . . . . . . . . . . . . . . -9-8-7 -6-5-4 -3 -2-1 0 1 2 3 4 5 6 7 8 9 
-3<x<2
DISTANCES
. . . . . . . . . . . . . . . . . . . -9-8-7 -6-5-4 -3 -2-1 0 1 2 3 4 5 6 7 8 9 
2 UNITS
. . . . . . . . . . . . . . . . . . . -9-8-7 -6-5-4 -3 -2-1 0 1 2 3 4 5 6 7 8 9 
2 UNITS
. . . . . . . . . . . . . . . . . . . -9-8-7 -6-5-4 -3 -2-1 0 1 2 3 4 5 6 7 8 9 
6 UNITS
DISTANCES 
In ALGEBRA
DISTANCE FROM ZERO TO 
ANY POINT x 
/x/
/x/ = 
X , if x>0 
-X , if x<0 
0 , if x=]0
DISTANCE BETWEEN ANY 
TWO POINTS X and Y 
/X-Y/
REAL NUMBERS

REAL NUMBERS