1. Lesson 2.3 Subtracting Integers View in “Slide Show” mode

2. Add the Opposite! Addition and subtraction are inverse operations – They “undo” each other. Instead of subtracting a number, you can add its opposite How about we “add the opposite” Great Idea!

3. Add the Opposite -2 - (- 4) -2 + ( + 4) Change the subtraction sign to a + sign Change the next integer sign to its opposite Use the addition rules you’ve already learned.

4. Add the Opposite -2 + ( + 4) Different signs, so find the difference (-,+) Think: 4 – 2 = 2 Use the sign of the number with the greatest absolute value (positive 4) Answer: +2 or 2

5. Add the Opposite! 3 - 2 3 + - 2 Change the subtraction sign to a + sign Change the next integer sign to its opposite Use the addition rules you’ve already learned. This one is easy! 3 – 2 = ?

6. Add the Opposite 3 + - 2 Different signs, so find the difference (+,-) Think: 3 – 2 = 1 Use the sign of the number with the greatest absolute value (positive 3) Answer: +1 or 1

7. Add the Opposite! -2 - 4 -2 + - 4 Change the subtraction sign to a + sign Change the next integer sign to its opposite Use the addition rules you’ve already learned.

8. Add the Opposite -2 + - 4 Same signs, so find the sum (-,-) Think: 2 + 4 = 6 Use the same sign of the integers (negative) Answer: -6

9. Add the Opposite! -4 - (- 2) -4 + ( + 2) Change the subtraction sign to a + sign Change the next integer sign to its opposite Use the addition rules you’ve already learned.

10. Add the Opposite -4 + ( + 2) Different signs, so find the difference (-,+) Think: 4 – 2 = 2 Use the sign of the number with the greatest absolute value (positive 4) Answer: -2

11. Add the Opposite! 5 - (-2) 5 + ( + 2) Change the subtraction sign to a + sign Change the next integer sign to its opposite Use the addition rules you’ve already learned.

12. Add the Opposite 5 + ( + 2) Same signs, so find the sum (+,+) Think: 5 + 2 = 7 Use the same sign of the integers (positive) Answer: +7 or 7

13. Add the Opposite! -3 - 7 -3 + -7 Change the subtraction sign to a + sign Change the next integer sign to its opposite Use the addition rules you’ve already learned.

14. Add the Opposite! -3 + -7 Same signs, so find the sum (-,-) What is the answer? -10

15. Add the Opposite! -1 - (- 8) You try it -1 + (+ 8) Answer: +7 or 7

16. Add the Opposite! -2 - (- 6) You try it -2 + (+ 6) Answer: +4 or 4

17. Evaluate x - y X = -3 and y = 2 You try it -3 - 2 -3 + -2 Answer: -5

18. Evaluate x - y X = 4 and y = -6 4 - -6 4 + +6 Answer: 10

19. Find the difference between 32°F and -10°F 32 - (- 10) 32+ +10 42 42°F

20. Find the difference between 8°F and -5°F 8 - (-5) 8 + (+5) 13 13°F