helpful for stuent ppt on rationa number cass 8

1. RATIONAL
NUMBER
By-Nandini Rai
Class-8th A
Roll No.-27

2. INDEX
- Introduction
- Properties
- Rational Numbers on the Number Line

3. INTRODUCTION
- Rational Number are closed under the
operations of Addition ,Subtraction ,
Multiplication.
- x+2=17
x=17-2
x=15 because this value of x satisfies the
given equation.The solution 15 is a
NATURAL NUMBER.

4. - x+5=5
x=5-5
x=0 the solution gives theWHOLE NUNBER
0 (zero).
- x+18=5
x=5-18
x=-13 which is not a whole number.This led
us to think of INTEGERS,(positive and
negative)
- 2x=3
x=3/2
- 5x+7= 0
- x= -7/5

5. PROPERTIES
 Commutivity
1) Whole numbers
2) Integers
3) Rational number
a) Addition is commutative for Rational
Numbers.
b) Subtraction is not commutative for
Rational Numbers.

6. - 3/2 and -7/5 this leads us to the collection of
RATIONAL NUMBER.
- A number which can be wrttten in the form
p/q where p and q are integers and q=0
cancel is called RATIONAL NUMBER.
- For example; -2/3, 6/7 are all rational
number.

7. c) Multiplication is commutative for RATIO-
-NAL NUMBERS.
d) Division is not commutative for
RATIONAL NUMBER.
 Associativity
1) Whole Numbers
2) Integers
3) Rational Number
a)Addition is Associative for Rational
Number.

8. c b) Subtraction is notAssociative for Rational
Numbers.
c) Multiplication is Associative for Rational
Numbers.
d) Division is not Associative for Rational
Numbers.
 Distributivity
- Distributivity of Multiplication over Addition
and Subtraction.
- For all rational numbers a,b and c.
- a(b+c) = ab+ac
a(b-c) = ab-ac

9.  Reciprocal
-We say that 21/8 is the Reciprocal of 8/21
and 7/-5 is the reciprocal of -5/7. 0(zero) has
no Reciprocal.
-We say that a Rational Number c/d is called
the Reciprocal or Multiplicative inverse of
another rational number a/b if a/b x c/d = 1

10. RATIONAL NUMBERS ON THE
NUMBER LINE
1) Natural Numbers
1 2 3 4 5 6 7
2) Whole Numbers
0 1 2 3 4 5

11. 3) Integers
-3 -2 -1 0 1 2 3
4) Rational Numbers
-1 -1/2 0 ½ 1

12. THANKYOU
The End