Double Negative Integer Lesson

Integer Operations

Pay attention to the operation.

Adding Integers

• 3 + 5 Adding two positive integers results in a positive sum.

• 3 - 5 --> 3 + (-5) Use the stronger sign, and subtract.

• -3 + 5 Use the strong sign, and subtract.

• -3 - 5 --> -3 + (-5) Adding two negative integers results in a negative sum.

Multiple Choice

$$5+4$$  

• 20

• 9

• 1

Multiple Choice

$$-9+2$$  

• -11

• -7

• -18

• 11

Multiple Choice

$$5-(-5)$$  

• 0

• 10

• 1

• -10

Multiple Choice

$$8+(-7)$$  

• 15

• 56

• 1

• -56

Subtracting Integers

If it helps, rewrite as addition!

• 3 - 5 is also written as 3 + (-5)

• -3 - 5 is also written as -3 + (-5)

• 5 - (-3) is also written as 5 + 3

• -5 - (-3) is also written as -5 + 3

 $-5--1$  is the same as  $-5\ +\ 1$  

You can rewrite this as:  $-5\ +\ 1$  because of the double negative!
 $-5\ +\ 1\ =\ -4$  
so
 $-5\ --1\ =\ -4$  

Multiple Select

Rewrite 9 - (-6)

• 9 + 6

• -9 + 6

• 9 + (-6)

• 9 - (-6)

Multiple Choice

$$3-(-7)$$  

• -4

• -10

• 4

• 10

Multiple Choice

$$-18-7$$  

• -25

• -11

• 11

• 25

Multiple Choice

$$7\ +\ \left(-12\right)$$  

• 19

• -84

• -5

• 5

Multiplying and Dividing Integers

• Same sign, positive answer

• Different sign, negative answer

• Remember to multiply or divide!!

Multiply/Divide all positives or all negatives.

•  $\frac{8}{2}\ =\ 4$  
  

•  $-8\ \div\ -2$   
  

•  $8\left(2\right)\ =\ 16$  
  

•  $-8\ \cdot\ -2\ =\ -16$  
  

Multiple Choice

$$\frac{2}{2}$$  

• 1

• 4

• 0

Multiple Choice

$$-9\left(-3\right)$$  

• -11

• -6

• -27

• 27

Multiple Choice

$$-11\ \cdot\ 3$$  

• -8

• 33

• 8

• -33

Multiple Choice

$$-12\ \div\ 6$$  

• 2

• -2

• -6

• 6

Multiple Choice

$$-30\ \div\ -6$$  

• -36

• 36

• -5

• 5

Poll

How do you feel about integer operations?

• I still need help.

• Just a bit more practice.

• I get it.

• Ready for a challenge.