1. Notes 2.4 Number Patterns: Prime Factorization A prime number has exactly two factors: 1 and itself. Two is the only even prime number. A composite number has more than two factors. The number 1 is neither prime nor composite. Example: 81 = 3*3*3*3 or 3^4 You can write the prime factorization as the product of factors or exponentially. We will do the prime factorization by dividing by prime numbers.

2. URL of the day: http://amby.com/educate/math/2-1_fact.html http://ccins.camosun.bc.ca/~jbritton/jbprimefa ctor.htm

3. homework answers 7)1–neither, 2-prime, 3-prime, 4-composite, 5=prime, 6-composite, 7-prime, 8- composite, 9-composite, 10-composite, 11-prime, 12-composite, 13-prime, 14- composite, 15-composite, 16-composite, 17-prime, 18-composite, 19-prime, 20- composite, 21-composite, 22-composite, 23-prime, 24-composite, 25-composite 9)2 3 x7 11) 2 4 x3 2 13) 2 4 x3 2 x5 15) 2x3x5x7x11 17) 105 19) 54 21) 90

4. 23) 26; composite 32) B 33) D 34) C 35)mpa: Numerals are written as the product of their prime factors; 28, you need to know the symbol for 13. SR 1) 9x5, 45x1, 15x3 2)8x6, 12x4, 16x3, 24x2, 48x1 3)9x8, 12x6, 18x4, 24x3, 36x2, 72x1 4)10x8, 16x5, 20x4, 40x2, 80x1 5)27 6) 110 7) 57 8) 60 – x = 8; $52 9) E 10) G 11) C 12) B 13) F 14) D

5. 15) 39; 78 16) 25; 22 17) 101; 104 18) 48; 24 8)2 4 x3 10) 2x3x5 2 12) 2 5 x3x7 14)3x5x11 2 16) 66 18) 56 20) 84 22)11; prime 24) 41; prime 28) 35 29)36 30) 18 or 24 MCA 1)5x9(9+2)=55 2) 45-6x(2+3)=15 3) 36/(3+6)/2=2 4) (27-18)/(6-3)=3

6. 5) 125 6) 64 7) 243 8) 64 9) C 10) A 11) D 12) B 13) 84x1, 42x2, 28x3, 21x4, 14x6, 12x7 14) 130 15) 132 16) 225 17) 252 18) false; 2 3 is the same as 2x2x2 or 8 19) true 20) false; the expression (6x8)- (6/2) is equal to 45. 21) true 22) Yes; three divides evenly into both the length and the width.