Explanation
In Third Century B.C. a Greek Mathmatician " Eratosthenes " developed a table to List all the Prime Numbers and Composite Numbers between 1 to 100. This method is known as " Sieve of Eratosthenes"
The Table developed by him is as:-
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 |
The Steps to be followed are as:-
Step 1 = Strike Out 1 because 1 is neither a Prime Number nor a Composite Number.
Step 2 = Write 2 in bold.
Step 3 = Strike Out all the Multiple of 2 other than itself. e.g. 2, 4, 6, 8, 10, 12 ........and so on till 100.
Step 4 = After Step 3, the next non-strike number you will find is 3. Write 3 in bold.
Step 5 = Strike Out all the Multiple of 3 other than itself. e.g. 9, 15, 21, 27, ........and so on till 100.
Step 6 = After Step 5, the next non-strike number you will find is 5. Write 5 in bold.
Step 7 = Strike Out all the Multiple of 5 other than itself. e.g. 25, 35, 55, ........and so on till 100.
Step 8 = After Step 7, the next non-strike number you will find is 7. Write 7 in bold.
Step 9 = Strike Out all the Multiple of 7 other than itself.
Step 10 = Continue this process, untill all the numbers in the table are either Strike out or written in Bold.
Step 11 = All the Strike Out Numbers are Composite Numbers (except 1).
Step 12 = All those numbers which are written in Bold are Prime Numbers. |
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