1. © 2007 M. Tallman Factor- a number that is multiplied by another. = 12 3 4 × factor 4 12 3 ÷= Factor- a number that divides evenly into another.

2. © 2007 M. Tallman Composite Number – a number that has more than two factors. 12 1 × 12 2 × 6 3 × 4 112 2 6 3 4,,,,,

3. Prime Number – a number that has only two factors, 1 and itself. 2 1 × 2 12, 3 1 × 3 13, 5 1 × 5 15,

4. 4, 6, 8, 9, 10, 12, 14, 15… Note: Every whole number from 2 on is either composite or prime Composite numbers… 2, 3, 5, 7, 11, 13, 17, 19… Prime numbers…

5. © 2007 M. Tallman 1 is neither prime nor composite. It is not prime because it does not have exactly two different factors. It is not composite because it does not have more than two factors.

6. © 2007 M. Tallman 100999897969594939291 90898887868584838281 80797877767574737271 70696867666564636261 60595857565554535251 50494847464544434241 40393837363534333231 30292827262524232221 20191817161514131211 10987654321 1 – Cross out 1; it is not prime. 2 – Leave 2; cross out multiples of 2 3– Leave 3; cross out multiples of 3 4– Leave 5; cross out multiples of 5 5– Leave 7; cross out multiples of 7 All the numbers left are prime!

7. © 2007 M. Tallman 16 1 × 16 2 × 8 4 × 4 5 1 × 5 10 1 × 10 2 × 5 11 1 × 11 List the factors for each number and determine if the number is composite or prime.

8. © 2007 M. Tallman 23 1 × 23 2 1 × 2 14 1 × 14 2 × 7 28 1 × 28 2 × 14 4 × 7 List the factors for each number and determine if the number is composite or prime.

9. © 2007 M. Tallman 30 1 × 30 2 × 15 3 × 10 29 1 × 29 3 1 × 3 40 1 × 40 2 × 20 4 × 10 5 × 65 × 8 List the factors for each number and determine if the number is composite or prime.