How do you determine differences in real world contexts?

1. How do you determine differences in real world contexts? For example: An airplane is at 392 feet above sea level. A submarine is at 69 feet below sea level. How far above the submarine is the airplane?

2. In this lesson you will learn how to subtract rational numbers by using real world contexts.

3. Subtracting means add the additive inverse. 4 - (-6) = 4+(+6) = 10

4. Does your answer make sense? 100 feet 100 ft 0 ft 75 ft ??? -25 feet

5. 392 - (-69) = 392 ft An airplane is at 392 feet above sea level. A submarine is at 69 feet below sea level. How far above the submarine is the airplane? 392 + (+69) = 461 0 ft | 461 | = -69 ft 461 feet

6. 5 -3 - 15 0 -3 + (-15) The temperature at 5pm was -3°F. It then dropped 15° by 10pm. What was the temperature at 10pm? 5pm -3° = 18 - -5 -10 Dropped 15° -15 10pm -18° -20 -25

7. In this lesson you have learned how to subtract rational numbers by using real world contexts.

8. A hot air balloon was at an elevation of 318 feet. A scuba diver was at 123 feet below sea level. How far above the scuba diver was the hot air balloon?

9. 318 - (-123) = A hot air balloon was at an elevation of 318 feet. A scuba diver was at 123 feet below sea level. How far above the scuba diver was the hot air balloon? 318 ft 318 + (+123) = 441 0 ft | 441 | = 441 feet -123ft

10. You overheard a radio announcer report that from 12:00pm to 3:00pm the temperature went from -5°F to -10°F. He said, “It is getting warmer.” Was he correct? Explain your reasoning.

11. Continue on next two slides An office building in downtown Atlanta has 32 floors above ground. It also has a parking garage with 6 floors below ground for parking. Henry parks on the third floor below ground and works on the 25th floor. Janis works on the top floor and parks on the lowest floor. Albert works on the 15th floor but parks on whatever floor he can.

12. Continued from Previous Slide Draw a picture showing the office building and parking garage. But sure to include the floor numbers. How many total floors does the building and parking garage have?

13. Continued from Previous Slide • 3. Let’s consider a day of traveling up and down the building for Henry. • When Henry arrives to work in the morning, how many floors does he travel to get to his office? • Henry decides to go to lunch with Albert. How many floors does he travel to get to Albert’s office? Which direction did he travel? • If Henry drives to lunch, how many floors do they travel from Albert’s office to Henry’s car? • Albert and Henry go to lunch and then Henry returns to his office. How many floors in total did Henry travel from the time he left his office to the time he returned back to his office after lunch?

14. Mt. Everest has an elevation of 29,035 feet above sea level. The Dead Sea has an elevation of 1,348 feet below sea level. What is the difference in elevation between Mt. Everest and the Dead Sea?

15. The temperature on Mars may reach a high of 70°F at the equator in the summer. It may reach a low of -225°F at the poles. Which expression gives the difference between those temperatures? A. 225°F - 70°F B. -70°F + 225°F C. 70°F - 225°F D. 70°F -(-225°F)