Integer Operations

Integer Operations

Pay extra attention to the operating sign.

Adding Integers

• If the signs are the SAME, ADD and KEEP the same sign. Ex: -13 + -27 = -40

• If the signs are DIFFERENT, SUBTRACT and use the sign of the STRONGER number. Ex: -24 + 5 = -19

Multiple Choice

-9 + (-8) = x

• x = 1

• x = -1

• x = 17

• x = -17

Multiple Choice

-15 + (-13) = x

• x = 28

• x = -18

• x = -28

• x = -12

Multiple Choice

It is a cold winter day in Virginia, the temperature when I woke up this morning was

 $-9\degree.$  At noon, the temperature increased by  $8\degree$ .  What was the temperature at noon? 

•  $-1\degree$  

•  $-4\degree$  

•  $4\degree$  

•  $12\degree$  

Subtracting Integers

• Rewrite as an addition problem.

• ADD the OPPOSITE

• Ex: 5 - (-2) becomes 5 + (+2) = 7

Multiple Choice

Rewrite -9 - (-3) using "add the opposite" strategy.

• -9 + 3

• 9 + (-3)

• 9 - (-3)

• 9 + 3

Multiple Choice

Evaluate: 7 - (-5) = x

• x = -2

• x = 2

• x = -12

• x = 12

Multiple Choice

Evaluate: -6 - (-22) = x

• x = 16

• x = -16

• x = 28

• x = -28

Poll

How do you feel about adding and subtracting integers?

• Awesome! I got it!!

• I'm at 75% or higher.

• I'm between 50% and 75%.

• I totally don't get it and need help.

Multiplying and dividing Integers

• Same sign, POSITIVE answer.

• Different sign, NEGATIVE answer.

• Don't forget to multiply or divide. :-)

Multiple Choice

 $\frac{2}{2}$  

Evaluate:

• 1

• 2

• 0

• 4

Multiple Choice

Evaluate:  $-11\ \cdot\ 3=$  x

• x = 33

• x = -33

• x = -14

• x = -8

Multiple Choice

Evaluate: (+7) (7) = x

• x = 14

• x = 0

• x = -49

• x = 49

Multiple Choice

 $-99\ \div\ \left(-11\right)\ =x$  

Evaluate:

• x = 9

• x = -9

• x = 110

• x = -110

Multiple Choice

You take 6 steps forward and 8 steps back. How many steps have you taken?

• 2

• -2

• 14

• -14

Multiple Choice

During the hot summer months, the height of the water in my pool decreases by 4 inches each week. What is the change in height over a six week period?

• 24 inches

• 10 inches

• -24 inches

• -10 inches

Multiple Choice

Last night, the temperature changed at a rate of -3 F per hour.  How long did it take for the temperature to change -33 F?

• 11 hours

• -11 hours

• 36 hours

• -36 hours

Multiple Choice

During a 12 hour period, the temperature dropped 48 degrees F. How many degrees did the temperature drop each hour?

• $4\degree F$

• $-4\degree F$

• $56\degree F$

• $-56\degree F$

Open Ended

Overall, how do you feel about operations with integers? Write in a complete sentence, your strengths and weaknesses with integers.