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Tuesday, January 14, 2014

Pam's Scribe Post

integers lesson
 
When multiplying integers, here is the basic lesson.
Here's an example:
(+7) x (+2)=
In words, this would be seven groups of positive 2.
In repeated addition: (+2) + (+2) + (+2) + (+2) + (+2) + (+2) + (+2) =
You could use integer chips as so:


The red symbolizes positive.

You can also represent this equation as a number line, either vertical or horizontal.


And you'll have your answer, which is (+14).

Here's something new:

scribe rule
 
When the integers have the same value (+ or -), the product is positive.
When the integers have different values (+, - ), the product is negative.
 
Let's apply this rule.
(+5) x (+4) =
Just multiply and then see whether or not the signs match or not.
5x4= 20
both positive, so the answer is positive.
(+ 5) x (+4) = +20)
 
(-6) x (+2)=
Multiply, 6x2= 12
They have different signs, meaning it's negative.
 
(-7) x (-8)=
Find the answer of 7x8, = 56
Then to see whether 56 or the answer is positive or negative, check the signs.
The two signs are the same, meaning the answer is going to be positive.
= (+56)
 
sign rule part 2
 
When multiplying integers , count the negative signs. When the number turns out to be an even number, it is going to be a positive product, and an odd number while counting equals to a negative product.
 
For example: (+4) x (+6) x (-7) x (-1) =
count the negative signs, and there are 2.
2 is an even number, therefor the answer will turn out to be a positive product.
 
To solve it, just do order of operations.
 
(+4) x (+6) x (-7) x (--1) =
(+24) x (-7) x (-1) =


(-168) x (-1)=
(+168) = answer. :)
See, it's a positive product.

Let's try this again.
(-4) x (-1) x (-3) x (+2) =
by following the same rule from before, this must be a negative product since there are 3 negative signs, and 3 is odd.

(-4) x (-1) x (-3) x (+2) =
(+4) x (-3) x (+2) =
(-12) x (+2)=
(-24) = answer
                                       
Let's try with more factors.
(-4) x (+2) x (-1) x (+1) x (-5) x (+1) =
There are 3 negatives, and 3 is an odd number meaning that the answer is going to be a negative product.

(-4) x (+2) x (-1) x (+1) x (-5) x (+1) =
(-8) x (-1) x (+1) x (-5) x (+1) =
(+8) x (+1) x (-5) x (+1) =
(+8) x (-5) x (+1) =
(-40) x (+1) =
(-40)= answer.
See it wasn't that bad.
If you're having problems with multiplying integers, please refer to the video below,





























P
Please feel free to play this game, and apply the sign rules to your answers. :)


Integer Multiplication Game

Have fun, and Good Luck! :)

3 comments:

  1. Great job with the pictures! They were very easy to understand and your explanations were very useful! Thanks for adding both, games and video too! Good job man(:

    ReplyDelete
  2. Thanks for this descriptive explanations! that game looks fun! thank you!

    ReplyDelete
  3. you really did a great job pam in explaining this, :)

    ReplyDelete

 

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