Subtracting Rational Numbers Warm Up Subtracting Rational Numbers
Subtracting Rational Numbers
Warm Up •
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 2
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.
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?
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?
Find the absolute value of the difference between -11 and -5.
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?
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?
- Slides: 11