Multiply and divide integers

​Multiply and Divide integers

​REMEMBER

If there is no sign in front of a number.....


the number is positive

Multiple Choice

Alex thinks that if you multiply a negative and a positive that you will get a negative answer ALWAYS!
His friend Tyler said he was wrong and the sign in your answer depends on how big and small the numbers are. Who is CORRECT? 

• Alex 
• Tyler

Answer is negative

​Different Sign

Answer is positive

Same Sign

General rule of Multiplication and Division

Multiple Choice

Is the product
–8 • (–3) positive or negative?

• negative

• positive

• both

• neither

Multiple Choice

-2 (-1) = ?

• -2

• 2

• -1

• 1

Answer is NEGATIVE

Odd number of negatives

Answer is POSITIVE

​Even number of negatives

An easier way...Count the number of negatives

Multiple Choice

(-1)(-1)(-1)(-1)(-1)

• 1

• -1

• 11,111

• -11,111

Multiple Choice

$$\frac{-56}{-13}$$

The answer will be ...

• positive

• negative

• can not tell until it is solved

Multiple Choice

$$-6\cdot-3\cdot2\cdot-5$$

The answer will be ...

• positive

• negative

• can not tell until it is solved

Multiple Choice

$$-2\cdot\frac{36}{-6}$$

The answer will be ...

• positive

• negative

• can not tell until it is solved

Multiple Choice

$$\frac{-350}{-15}\div-2.1$$

The answer will be ...

• positive

• negative

• can not tell until it is solved

The counting only works as long as there is ONLY multiplication or division.

If there is ANY addition or subtraction you will have to do the math!

​

NOTE

Multiple Choice

$$\left(-3\cdot-2\cdot-1\right)-\frac{-35}{5}$$

The answer will be ... (by just COUNTING the negatives)

• positive

• negative

• can not tell until it is solved

Fill in the Blanks

Multiple Choice

The football team lost 8 yards on every play for 5 plays. Which integer shows the total number of yards the team has lost? 

• 40
• -40
• 3
• -3

Fill in the Blanks

Multiple Choice

If the temperature drops 5 degrees every hour for 9 hours, which integer represents the change in temperature? 

• 14
• -14
• 45
• -45

Fill in the Blanks

Multiple Choice

Over a 6 week period, the price of a gallon of gas increased by 18 cents.  What was the average change per week?

• -3 cents
• 3 cents
• 108 cents
• -108 cents

Fill in the Blanks

Multiple Choice

Tammy had $450 in her bank account. During the week she purchases 4 fast food meals at a cost of $12.50 per meal, 8 gallons of gas at a cost of $3.25 per gallon, and deposited a $50 birthday check from her grandmother. What is the new balance in her bank account?

• $424.00

• $484.25

• $375.00

• $274.00