1. 4 3 2 1 0 -2 -3 It is 2 o C The temperature drops by 3 degrees What temperature is it now? -1 o C

2. 4 3 2 1 0 -2 -3 It is 4 o C The temperature drops by 5 degrees What temperature is it now? -1 o C

3. 4 3 2 1 0 -2 -3 It is -2 o C The temperature rises by 3 degrees What temperature is it now? +1 o C 4 3 2 1 0 -2 -3 4 3 2 1 0 -2 -3 4 3 2 1 0 -2 -3

4. 4 3 2 1 0 -2 -3 3 - 4 = 4 3 2 1 0 -2 -3 4 3 2 1 0 -2 -3 4 3 2 1 0 -2 -3 4 3 2 1 0 -2 -3 This is a negative number

5. It is 10 o C The temperature drops by 15 o C What is the temperature now? -5 o C 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15

6. It is 15 o C The temperature drops by 20 o C What is the temperature now? -5 o C 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15

7. 15 - 20 =-5 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15

8. -15+10 =-5 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15

9. -15+20 =+5 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15 20 15 10 5 0 -5 -10 -15

10. WELL DONE!!