Docstoc

Subtracting Integers (PowerPoint)

Document Sample
Subtracting Integers (PowerPoint) Powered By Docstoc
					    4 Steps to Subtracting Integers
1. Rewrite the first number.
2. Change operation sign from
   subtraction to addition.
3. Change the second number to its
   opposite. – to +, + to –
4. Follow the rules for adding integers
   and solve.
  For example...
  ( 9 )  ( 7 ) 
   Becomes...

  (9)  (7)  2

“Add the opposite.”
 12  9 
 12  ( 9)   21
 13  19 
 13  ( 19)   6
( 9)  ( 17) 
(9)  (17)  8
4
3
2
1
0
     3 - 4 = -1
-1
-2
-3
20
15
                It is   10oC
10
5
0     • The temperature drops by 15oC
-5    • What is the temperature now?
-10
-15


              -5 oC
20
15
10
               It is 15oC
5     • The temperature drops by
0       20oC
-5    • What is the temperature
-10     now?
-15



             -5 oC
 Now let’s mix up some
addition and subtraction
       problems.
   9  17  8             29  ( 8) 
                           29  (8)   21
  22  ( 5) 
  22  (5)  27           19  23 
                          19  ( 23)   4

28  ( 11)  17           9  ( 15)   24

Sample Problems (Mixed)
      Just remember:
Always change a subtraction
  problem into an addition
       problem first!

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:6
posted:2/13/2012
language:English
pages:15