How to find Prime Numbers from 1 to 100.

How to find Prime Numbers from 1 to 100 Easy Method...... Sieve of Eratosthenes.

Round 1 : Cross out 1 because it is not a prime number.

Round 2 : Encircle 2, cross out all the multiples of 2, other than 2 itself, i.e. 4, 6,

8 and so on.

Round 3 : You will find that the next uncrossed number is 3. Encircle 3 and cross

out all the multiples of 3, other than 3 itself.

Round 4 : The next uncrossed number is 5. Encircle 5 and cross out all the multiples

of 5 other than 5 itself.

Round 5 : Continue this process till all the

numbers in the list are either encircled or

crossed out.

All the encircled numbers are prime

numbers. All the crossed out numbers,

other than 1 are composite numbers.

This method is called the Sieve of

Eratosthenes.