What is Prime Number

Prime numbers are whole numbers greater than 1. Each prime number has exactly 2 factors.

Prime Number Facts

1) The number 1 has only one factor.

2) The number 1 is neither prime not composite.

3) The number 2 is the smallest prime number.

4) The number 97 is the largesttwo digit prime number.

5) The only even prime number is 2.

6) Zero and 1 are not considered prime numbers.

Tricks to find the Prime number 1 to 100 in 2 minutes.

Step1:

Draw the table and fill the numbers 1 to 100.

Step2:

Circle the prime number 2 and then cross out every second number. This means you have crossed out all multiples of 2.

Step3:

Circle the next prime number 3 and then cross out every third number. This means you have crossed out all multiples of 3.

Step4:

Circle the next prime number 5 and then cross out every fifth number. This means you have crossed out all multiples of 5.

Step5:

Circle the next prime number 7 and then cross out the mutiples of 7 that are not crossed out.

Step6:

The number not crossed out are all prime numbers.

2 , 3 , 5 , 7 , 11, 13 , 17 , 19 , 23 , 29 , 31 , 37 , 41 , 43 , 47 , 53 , 59 , 61 , 67 , 71 , 73 , 79 , 83 , 89 , 97