NUMBERS

PLACE VALUE AND FACE VALUE  (OR LOCAL VALUE) OF ADIGIT IN NUMERAL

 (i)  The face value of a digit in numeral is its own value , at what ever place it may be 

EX. In the numeral 6872 , the face value of the 2 is 2 , the face value of the 7 is 7  , the  face value of 8 is 8 and  the face  value  6 is 6 

(ii)  In the given numeral : 

place value of the unit digit = (unit digit )* 1

the place value of the  tens digit = (tens digit )*10

place value of the hundred digit = (hundred)* 100   and so on

EX. In the numeral 70984 we have

 Place value of 4 = 4*1=4

place value of the 8 = 8*10 =80

place value of the 9 = 9*100=900

place value of  the 0=0

place value of the 7 =7*10000=70000

EVEN AND ODD NUMBERS

Even numbers :- A counting number divisible by 2 is known as even no.
for e.g 0,2,4,6,8,10 so on these are the even numbers ..

Odd numbers :- A counting number which are not divisible by 2 are known as  odd number

for e.g 1,3,5,7,9,11 so on are odd numbers 

PRIME NUMBERS 

A counting number id called a  prime no. if it has exactly two factors  namely itself and 1

EX.  2,3,5,7,9,11,13.17,19,23,29.31.37.41.43.47.53.59.61,67,71,73,,79,83,,89,97,

TEST FOR A NUMBER  TO BE  PRIME 

Let p be the number and n be the smallest counting number such that (n^2>p) n square is greater then & equal to the p

now test p is divisible by any of prime  no. less than or equal to the n

if yes than p is not prime otherwise p is prime ..

EX.

137 is prime no . or not prime no.

12^2 is less than 137
prime no. less  than 12 are 2,3,5,7,9,11
none of these are divisible by the  137
.'. 137 is a prime number ..

THE ABOVE  DIAGRAM SHOWS THE EVEN AND ODD PRIME NUMBERS