1. Warmup 1.6 Find the sum: -14 + (-32) -8 + 22 27 + (-16) + (-12)
Find the difference
5.7 – ) 6.5 – 5.88

2. Objective: Subtract integers
Section 1.6
Objective: Subtract integers

3. Vocabulary
Yeah, No new vocabulary today 

4. Rule for Subtracting Integers
ADD the opposite!
“K F C”
Keep the first number
Flip subtraction to addition
Change the second number to its opposite
EVERY time you see subtraction…Change it to Addition!!!

5. Example 1 4 – 10 7 – (-5) -2 – (-9) K F C 4 + (-10) = -6 K F C 7 + 5
Different signs
Subtract, sign of larger K F C 7 + 5
=12
Same sign
Add, keep sign K F C -2 + 9
= 7
Different signs
Subtract, sign of larger

6. Example 2 Evaluate the expression when x = -9 x – (-40) 7 - x
= -9 – (-40) K F C
Different signs
Subtract, sign of larger -9 + 40
= 31
= 7 – (-9) K F C
Same signs
Add, keep sign 7 + 9
= 16

7. Your turn
Find the difference
Evaluate when y = -14

8. Evaluating Change Use subtraction to find the change in a quantity
Examples: Elevation, temperature
Change = Final – Original
“CFO”

9. Example 3 Find the change in temperature from -15°C to 10°C
Change = Final – Original
= 10
- (-15) K F C
= 10 + 15
= 25°C

10. Your turn Find the change in temperature From 32°F to -10°F
From 8°C to -3°C
From -2°C to 15°C

11. Pre Alg. Classwork 1.6 Find the difference
Evaluate the expression when m = -6
9)Find the change in temperature from -5°F to -13°F

12. Closure Identify the mistake & fix the mistake: -5 – 7 K F C 5 + (7)
Step 1 K F C 5 +
(7)
Step 2
Step 3 12