2. Donna Reynolds Impact of Technology Assignment 1.17 My Powerpoint will be used to teach fifth grade math-specifically adding and subtracting positive and negative numbers. This is connected with the Massachusetts Curriculum Frameworks learning standard for grades 5 and 6. as follows: 6 N 6 Find and position integers, fractions, mixed numbers and decimals both positive and negative on the number line. 6 N 7 Compare and order integers (including negative integers) and positive fractions, mixed numbers, decimals, and percents. Subtracting negative numbers is included in the Everyday Math Program. The concept of adding and subtracting positive and negative numbers Can be challenging for students. The Powerpoint will introduce the concept and provide visuals of the rules to follow. There are also links to Websites to provide further reinforcement with tutorials, games, and practice problems.

3. Adding and Subtracting Positive and Negative Numbers 3+ -6 = -7 + 5 = -2 9 - -5 = 14

4. First, let’s look at the number line. Sure!Right!

5. Negative numbers are to the left of zero. Positive numbers are to the right of zero. THE NUMBER LINE

6. RULE 1: When adding numbers with like signs, add using the same sign. Adding: Forward to Slide 22

7. + + + - = + 2 + 3 = 5 + - = - - 2 + - 3 = - 5 Add using the same sign. Makes sense!

8. RULE 2: When adding numbers with unlike signs, use the sign of the larger number and subtract. Sounds tricky! Adding : Forward to slide 22

9. + + - = Use the sign of the larger number and subtract. +5 + - 3 = +2 The number 5 is larger than 3 so use a positive sign in the sum. - - 5 + 3 = - 2 The number 5 is larger than 3 so use a negative sign in the sum. For Example: Oh,,, I see.

10. +++++ --- +5 + - 3 = +2 Do you see there is a balance of +2 ?

11. +++ --- -5 + + 3 = -2 Do you see there is a balance of -2 ? --

12. Try this….. 9 + -3 = ? ????

13. +9 + -3 = +6 Exactly! 9 is larger, so subtract and use a positive sign

14. Try this….. -7 + +2 = ? ????

15. -7 + +2 = - 5 Exactly! 7 is larger, so subtract the two numbers and use a negative sign.

16. Rule 3: To subtract a positive or negative number, add the opposite number. Subtracting Yikes ! Forward to Slide 22

17. The opposite of positive 7 is negative 7 I see!

18. The opposite of negative 7 is positive 7 I get it!

19. To subtract a positive or negative number, add the opposite number. +7 - +5 i s +7 + -5 = +2 For Example……. -7 - -5 i s -7 + +5 = -2 And…

20. -7 - +5 i s -7 + -5 = -12 7 - - 5 i s +7 + +5 = +12 And….. And look….

21. So….subtracting a negative number is like adding a positive. And… subtracting a positive is like adding a negative.

22. Precisely!!!

23. If you need to review the rules click the buttons below. Adding with like signs Adding with unlike signs Subtracting

24. Online Practice Adding and Subtracting Positive and Negative Numbers Adding with Color Chips Subtracting with Color Chips

25. Online Games Adding and Subtracting Positive and Negative Numbers “Eat the Fish” *(must use Internet Explorer) Fun Brain “Line Jumper”

26. 3+ -6 = -7 + 5 = -2 9 - -5 = 14 That’s how to add and subtract Positive and negative numbers. If you would like to review, you may Start over by clicking the arrow.