Joanna's Scribe Post

Subtracting Integers

2 0 1 4

♫ Whenever something is not there,

You must add a zero pair! ♫

             Whenever you're subtracting integers, you may see these types of equations...

6 - (-9) =            (-2) - (-5) =            6 - 7 =          -4 - 6 = 

Everything is combined but subtracting. You must remove when it's an equation with 2 negatives. 

6 - (-9) =        or       (-2) - (-5) = 

Instead of saying, have six and owe 9, you say, have 6 REMOVE owe 9. The positive always stays behind. If you find 2 negatives together, you always have more than what you're owing. For this question, instead of combining have 6 and owe 9, we remove the negatives. By doing so, we add zero pairs. Like this...

6- (-9) = 15

Have 6 remove owe 9 = have 15

            Step 1                 Step 2               Step 3                     Step 4    

              (-9)                Remove         +++++++++         +++++++++ ++++++    =     15

      +++++++++              -9            Add it with your             

      - - - - - - - - -       - - - - - - - - -   positive number

For this next equation, we do the same thing but instead of starting with a positive and a negative number, they will both be negative.

(-2) - (-5) = 3

Owe 2 remove owe 5 = have 3

            Step 1                 Step 2               Step 3                         Step 4    

              (-5)                 Remove            +++++                      ++ +++   = 3 

            +++++                  -5        Combine it with your         - - 

            - - - - -               - - - - -       negative number

These next equations will be different from removing. The next equations will not have 2 negatives together meaning that you'll combine without removing. 

6 - 7 =         or        -4 - 6 = 

6 - 7 = -1

Have 6 and owe 7 = owe 1

              Step 1                                          Step 2           

           ++++++          = -1                 Remove all zero 

           - - - - - -    -                      pairs and take what is left.

-4 - 6 = -10

Owe 4 and owe 6 = owe 10

For this equation, we're doing the same thing but replacing the positive number with a negative number.

               Step 1                                                            Step 2         

      - - - - - - - - - -  = -10                     For this step, you're practically combining

                                             whatever negative numbers you have with the negative sign.

Here is a video that may help you to use different equations through subtraction...

In case you need any practice for subtracting equations, please enjoy this game...

http://www.sheppardsoftware.com/mathgames/integers/FS_Integer_subtraction.htm

Hope you find subtracting easier know that you've read this.

GOOD LUCK!

January 8, 2014