The purpose is to create a list of prime numbers.
Difficulty: Easy
Time Required: enter time required here use increments of five minutes if you can t define a time please us n a 10
Here's How:
- List all integers up to the number of your choice, say 20: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
- X off all multiples of 2: 4 6 8 10 12 14 16 18 20
- X off all multiples of 3: 9 15
- This leaves 1 2 3 5 7 11 13 17 19, all of which are prime.
- If your number were larger, you would continue marking off all multiples of the next prime (5) and then the next (7), etc.
Tips:
- I have heard that 1 is no longer considered "prime". The non-prime numbers are referred to as composites. So, for step 4, you would have numbers that aren't "composites".
