1. L 2.5 Warm-Up Exercises FIND THE SUM OF THE MATRICES.

2. 2.5 Multiplying Real Numbers Multiplication Rules Objective: To multiply positives and negatives, including decimals and fractions!! 1.(6)(-4)2. -4c (5d) 3.(-1)(-12)4. 12 (-3) 5.- 2 -116. (7)(-7) 7.8 (-3)(2)8. -2 -6 -4 9. (-3b)(-4b)(-2z)(-5z)(-1) Does the number of negative values(signs) affect the sign of the product? How? Same signs  “+” Diff. signs  “–” Even “-” signs  “+” Odd “-” signs  “–” -24 -20cd -12 -36 22 -49 -48 -120 b 2 z 2

3. Multiplying Decimals What is the rule for multiplying decimals? Try these: Don’t forget the sign!! 10. (2.4)(-3.1)11. 4.2(1.14)12. (-5.3)(-0.04) 13. (2.93)(0.012)14. (-10)(3.56)(-2) Line up at the right and multiply as whole number, when finished, place decimal point from right for the total number of decimal digits. -7.44 4.788 0.212 0.03516 71.2

4. 5 Minute Brain Break USE THIS TIME TO relax and/or STETCH OUT…. Try this Brain Puzzle… In each sentence, an animal is concealed. The first sentence has dog concealed. Can you find the others? 1. What shall I do, Gertrude? 2. Asking nutty questions can be most annoying. 3. A gold key is not a common key. 4. Horace tries in school to be a very good boy. 5. People who drive too fast are likely to be arrested. 6. Did I ever tell you, Bill, I once found a dollar? 7. John came late to his arithmetic class. 8. I enjoy listening to music at night.

5. Multiplying Fractions Try these: Don’t forget the sign!! 15.16.17. 18. 19. What is the rule for multiplying fractions? What should you do to make whole numbers look like fractions? Diagonally or vertically cancel the greatest common factor between any numerator and denominate and then multiply the numerators and denominates. Just put a dummy denominate “1”.

6. Properties of Multiplication DefinitionExample Commutativea · b = b · a Associative(a · b) · c = a ·(b · c) Identitya · 1 = a 4 · (-2) = (-2) · 4 [(-4) · 3] · (-2) = (-4) · [ 3 · (-2)] (-2) · 1 = -2 Ex. (2) (–x) = –2x 3 (–n)(–n) = 3n 2 –(y) 4 = –(y·y·y·y) = –y 4

7. Multiplying Negative X Negative Positive X Positve DecimalsFractions POSITIVE! Straight Across I Ignore Decimals Count Numbers Behind Decimals To Figure Out Where Decimal Goes Whole Numbers Positive X Negative Negative X Positive NEGATIVE! Summary

8. Daily Homework Quiz Find the Product. 1.(-2)(8)(-1) 2.(7)(-3)(-5)(-1/2) 3. Evaluate a³ + 2a² - a when a = -2 In-Class Assignment Textbook Pages 96 #’s 16-49 (All)