7th Grade Math

94 Integers

and Apply

Use counters or a drawing to find each difference.

1. 7 - 6 2. 5 - (-3) 3. 6 - (-3) 4. 5 - 8


2. 
   
   
   
   • 7 - (-2) 6. - 7 - 3 7. - 5 - (-7) 8. - 2 - 9
   
   
   
   

the Results

9. Write two subtraction sentences where the difference is positive. Use a
   combination of positive and negative integers.


10. Write two subtraction sentences where the difference is negative. Use a
    combination of positive and negative integers.


11. E WRITE MATH Jake owes his sister $3. She decides to “take away” his
    debt. That is, he does not have to pay her back. Write a subtraction sentence
    for this situation. Explain why subtracting a negative integer is the same
    as adding.

Use counters to find each difference.

• 6 - (-3)

Place 6 negative counters on the mat.

Remove 3 negative counters.

So, - 6 - (-3) = -3.

• 5 - 1

Place 5 negative counters on the mat.

• 
  
  
  
  • 
    
  
  
  
  


• 
  
  
  
  • 
    
    
    
    • Remove 1 positive counter. However,
      there are 0 positive counters.
    
    
    
    
  
  
  
  

Add 1 zero pair to the mat.

+

Now you can remove 1 positive

counter. Find the remaining number

of counters.

So, - 5 - 1 = -6.

086_098_C2L2_895130.indd 94 12/29/09 4:01 PM