|
|
Prime Numbers
These are positive whole numbers that have EXACTLY two factors- 1 and itself. Examples: 2, 5, 19, 73 |
Composite Numbers
These are positive whole numbers that have MORE than two factors. Examples: 4, 27, 48, 99 |
0
The number 0 is neither prime nor composite because it has an infinite amount of factors. Think about it: every number you multiply by zero gives you the product of zero! |
1
The number 1 is neither prime nor composite because it only has 1 factor, and to be prime it has to have exactly two. You can only multiply 1x1 to get a product of 1, and since the numbers are the same, there is only one factor. |
2
The number 2 is the only even prime number. Every other even number is also divisible by 2, so that it automatically has more than the two factors of 1 and itself. |
Factor T-Charts
|
Factor Rainbows
|
|
|
1 = Every number is divisible by 1.
2 = All even numbers are divisible by 2. 3 = A number is divisible by 3 if the sum of its digits is divisible by three. Example: 231 = 2 + 3 + 1 = 6, since 6 is divisible by 3, 231 is divisible by 3. 4 = A number is divisible by 4 if the last two digits of the number is divisible by 4. |
5 = A number is divisible by 5 if the last digit is 5 or 0.
6 = A number is divisible by 6 if it is also divisible by BOTH 2 AND 3. 9 = A number is divisible by 9 if the sum of the digits is divisible by nine. Example: 432 = 4+ 3 + 2 = 9, since 9 is divisible by 9, 432 is divisible by 9. 10 = A number is divisible by 10 if the last digit is 0. |
Odd or Even?
|
Divisibility Rules
|