1. Subtracting Rational Numbers

2. Warm Up

4. Subtracting Rational Numbers Recall that subtraction is formally defined as the addition of the additive inverse, or opposite. For example 5 – 3 is equivalent to 5 + (-3).2

5. Commutative Property does not Apply to Subtraction The commutative property does not apply to addition. For example 5 – 3 is not equivalent to 3 – 5. 2 -2 However, when subtraction is rewritten as the addition of the opposite, the commutative property does apply.

6. 5.5 – 7.257.25 – 5.5

7. A group of campers set up their tent at 6.25 meters above sea level. They hike down a valley and stop 9.5 meters below where they set up camp. What is the campers’ elevation when they stop?

8. Sheri ended the game with -8.5 points in a trivia game. On her last turn, she lost 6.25 points. How many points did she have before her last turn?

9. Find the absolute value of the difference between -11 and -5.

10. On Monday, your bank account balance was -$12.58. Since you didn’t realize this, you wrote a check for $30.72 for groceries. What is the new balance in your checking account? The bank charges a $25.00 fee for paying a check on a negative balance. What is the balance in your checking account after this fee? How much money do you need to deposit to bring your account balance back up to $0.00 after the fee?

11. Exit Ticket 1.-13 – (-5)2. -5 – 2.5 3.6.25 – (-3.5)4. -23 – 50 5.A scuba diver starts at 85.6 meters below the surface and descends until he reaches 103.2 meters below sea level. How many meters did he descend?