2. Prime Numbers A whole number greater than 1 whose only whole number factors are 1 and itself. 2 3 5 17

3. Composite number A whole number greater than 1 that has positive factors other than 1 and itself 123 6 12

4. Prime factorization Expressing a whole number as a product of prime numbers 2| 22 11 2 * 11

5. DIVISIBILITY RULES 2 -- ends in 0 2 4 6 8 3 -- the sum of the digits is divisible by 3 5 -- ends in 0 or 5 6 -- divisible by 2 AND 3 9 -- sum of digits is divisible by 9 10 -- ends in 0

6. Make a factor tree 20 2 x 10 (2 factors) 2 2 5 prime factors 2² ·5

7. Your Turn 45 120 99 54 36 52

8. Homework:Page 159 #12 #14 #16 #30 AND Page 160 #32 34 45 46 52 60 READ pages 162-165 take notes definitions & examples Example: 612 2 x 306 2 x 153 3 x 51 3 17 factors 2 3 51 153 306 (all unique numbers listed) prime factorization 2² ·3² · 17