2b. neg and pos
- 1. Positive and Negative Numbers Created by Richard Bull
- 2. Definition • Positive number – a number greater than zero. 0 1 2 3 4 5 6
- 3. Definition • Negative number – a number less than zero. 0 1 2 3 4 5 6-1-2-3-4-5-6
- 4. Negative Numbers Are Used to Measure Temperature
- 5. Negative Numbers Are Used to Show Debt If you get a loan from the bank for £5,000. If you were to look at your bank balance it would show -£5,000.
- 6. Negative Numbers Are Used to Measure Under Sea Level 0 10 20 30 -10 -20 -30 -40
- 7. Hint • If you don’t see a negative or positive sign in front of a number it is positive. 9+
- 8. Integer Addition Rules Rule #1 •If the signs are the same, pretend the signs aren’t there and add them. -9 + -5 = 14 Rule #2 •Ask which absolute number is bigger •now remember what sign it was, this is the sign for your answer -
- 9. Solve the Problems • -3 + -5 = • 4 + 7 = • -6 + -7 = • 5 + 9 = • -9 + -9 = -8 -18 14 -13 11
- 10. Integer Addition Rules Rule #2 •If the signs are different, 3 + -5 = pretend the signs aren’t there and subtract the smaller absolute number from the larger absolute number 5 - 3 = 2 Now look back at the original question and use the sign of the biggest absolute number for your answer 3 + -5 = -
- 11. Solve These Problems •3 + -5 = •-4 + 7 = •(+3) + (-4) = •-6 + 7 = •5 + -9 = •-9 + 9 = -25 – 3 = 2 0 -4 1 -1 3 9 – 9 = 0 9 – 5 = 4 7 – 6 = 1 4 – 3 = 1 7 – 4 = 3
- 12. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 When the number is positive count to the right. When the number is negative count to the left. +-
- 13. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 + - +3 + -5 = -2
- 14. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 + - +6 + -4 = +2
- 15. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 + - +3 + -7 = -4
- 16. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - + -3 + +7 = +4
- 17. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - + -5 + +3 = +4
- 18. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - + -2 + +8 = +6
- 19. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - + -5 + +2 = -3
- 20. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - - -4 + -2 = -6
- 21. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - - -2 + -3 = -5
- 22. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - - -1 + -4 = -5
- 23. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 - - -4 + -1 = -5
- 24. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 + + 4 + 1 = 5
- 25. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 + + 3 + 2 = 5
- 26. One Way to Add Integers Is With a Number Line 0 1 2 3 4 5 6-1-2-3-4-5-6 + + 1 + 5 = 6
- 27. Add integers with same signs: Add the numbers and keep the sign a)3 + 2 = 5 b) -4 + (-6) = -10 Add integers with different signs: Subtract the (absolute values) and keep the sign of the sign of the absolute value a) -7 + 4 = -3 b) 1 + (-9) = -8 Created by Richard Bull