2. Applications of Negative Numbers & Absolute Value In Algebra County

3. Zero Down here, temperatures are negative. Negative Numbers are found in weather reports, but not in sunny Florida!

4. There, the stock market went down. Negative Numbers are found in stock market quotes

5. When losing weight, the weight loss is a negative number.

6. The number of feet below sea level is a negative number.

10. Checks are “subtracted” from the bank statement. Negative Numbers are found in banking.

11. Negative Numbers are found in Jeopardy scores.

12. IN ALGEBRA COUNTY ADDING INTEGERS

13. If it’s 70 degrees outside, and the temperature gets 10 degrees cooler, how can we write it? If it’s -10 degrees outside, and the temperature goes down 10 degrees, how can we write it? A positive added to a negative takes the sign of the largest “number.” We subtract. If it’s 5 degrees outside, and the temperature gets 10 degrees colder, how can we write it? A negative added to a negative is a “larger” negative. We add the “numbers.”

14. Another way to think of adding positive and negative numbers is by using red and yellow colored counters. 3 and -5 zero pairs -3 and -5 No zero pairs

15. Write these in your notes pages

16. IN ALGEBRA COUNTY MULTIPLYING INTEGERS

17. -5 TIMES 6 CAN BE WRITTEN: -5(6)-5 ·6 (-5)(6) 2(3) MEANS: 2 GROUPS OF 3 A 2 BY 3 ARRAY

18. WE CAN PICTURE 2(3): THESE ARE ALL ARRAYS

19. WE CAN PICTURE 2(3) AS 2 GROUPS OF 3:

20. Which? Group or array? 3 keys on two key rings A six-pack of cokes Two rows of three kitchen tiles Two stacks of three books The chairs in church

21. When we multiply: Positive X positive = Positive X negative = Negative X positive = Negative X negative = + - - +

22. Don’t get confused: Positive + positive = Positive + negative = Negative + positive = Negative + negative = + ?? -

23. Negative + positive =?? Why the question marks? -4+6=2 (positive) -6+4= -2 (negative)

24. Back to multiplication: -(-3) means: - (-3)1 = 3 Negative 1 times negative 3 The number 1 is very important in Algebra County. Also: -(5) means: - (5) which is: -5 Negative 1 times 5 1

25. Let’s work some multiplication problems: -2(5)-10= 3(-5)-15= -4(-2)8= - (-6)6= -9(-11)99= - (-13)13=