### Scribe Post for October 27, 2008

4:02 PM

Today in class we learnt all about subtracting integers. Mr. Harbeck VERY clearly told us that INTEGERS DO NOT SUBTRACT, YOU ADD THE OPPOSITE (don't worry if you don't understand I will be explaining it in the methods.) Here are two methods that you can use to subtract integers.

METHOD #1- RE-WRITE THE QUESTION

INTEGERS DO NOT SUBTRACT, YOU ADD THE OPPOSITE.

For this method you have to re-write the question to make it easier on yourself. If the question says (+5)-(+3) you should replace the subtraction sign with an addition sign. That's the adding part. Now you replace the +3 with a -3. That's the THE OPPOSITE part. Then you just answer the addition question however you want. Now the question should look like this, (+5)+(-3)=(+2)

E.G. This is question #31 on page 46 (the yellow booklet).

That was one method of subtracting integers.

METHOD #2-DRAW INTEGER TILES

For this method you have to draw out the integer tiles (they can be circles too.) For example if the question says (-3)-(+3) you should draw out the first integer the same, and the second one should be a zero pair. Then you cross out the tiles that are the 2nd integer in the question. Then you just add up the remaining tiles and you have the answer! Here is a picture if you don't understand it yet....

E.G. This is question #20 on page 46 show as integer tiles. (the yellow booklet).

and this is the solution.
That was another method on how to subtract integers.
In class Mr. Harbeck also assigned page 46 in the yellow booklet for homework, and we got some time in class to do it.

#### 1 Response to "Scribe Post for October 27, 2008"

October 29, 2008 at 6:21 PM
Good job it really helps!