## Monday, March 7, 2011

### Marysa's Great Big Book of Integers

Chapter 1 Grade 7 Review

Things to Know.....
• Red=Positive
• Blue=Negative
• Can only be a whole # no decimals
• Zero Pairs (-6 and +6)
There is a song to remember when to use them:

When subtracting some thing that isn't there use a Zero Pair.

In Grade 7 we wrote integers like this....
(+6)+(-3)=

In Grade 8 we now remove the things in the
question that we do not need....
6-3=

We were told to think of it as money.

Example:
You have 6 dollars and you owe 3 dollars.

Homework

-6-(-4)=-2 You have to use a Zero pair to take -4 away from -6.

-10+6=-4
You would add 6 to -10 but because it is a negative # you are adding o
n to you match the negative # with a positive and you end up with -4.

6-7+
2=1
I wold first match the negative #'s with a positive from the first 2 numbers (6
and -7). Then I would add on the 2 once again using the Zero pairs to get the answer 1.

14-(-3)=17
In this question you are once again taking away something that is no there so you use the zero pairs. First you must add on 3 Zero pairs then you have a -3 that you can take away. Once you have you are left with 17.

-3-(-7)=4
You have to add on 4 zero pairs to take away some thing that is not there.

-3-
7=-10
You have -10 because you have to once again use zero pairs this time you would ad
d on 7 pairs.

3-7=-4
For this question you have to add on 4 zero pairs to get your answer.

3+7=10
This is just like any other addition question.

-3+7=4

This question equals 4 because the #'s make zero pairs.

Multiplying Integers

The questions:
1. (+2)x(+3)=
2. (+2)x(-3)=
3. (-2)x(+3)=
4. (-2)x(-3)=

Audioboo:

The first question can be look at as two groups of positive three. So the answer would be positive six.
The second question is almost the same as the first but the three in this question is negative. So instead of positive you have two groups of negative three.
The third question is like removing two groups of three. To do this you have to use zero pairs. After you have taken two groups of positive three away you are left with negative six.
The last question is like the opposite of the one before it. You still use zero pairs and are still removing two groups of something. The difference is you are removing a negative number instead of a positive one. When you have used the zero pairs you will be left with a positive number meaning six.

Dividing Integers

Partitive division is when you use the number line to divide the integer.

Example:
6÷2=3
-6÷(-2)=
Quotative division is when you use sharing to g

Example:

(-6)÷2=

Multiplicative Inverse is when you use multiplication to get your answer.

Example:

6÷(-2)=

(-2)x(-3)=6
(-3)x(-2)=6

that mean that the answer to the division question would be 3.

Sign Rules...

When there is no negative sign or there is an even numbers the answer will be positive.

Example: 6÷2=(+3) There is no negative signs.

Example: -6÷(-2)=(+3) There is an even number of negative signs.

When there is an odd number of negative signs the answer will be negative.

Example: (-6)÷2=(-3) There is an odd number of negative signs.

Example: 6÷(-2)=(-3) There is an odd number of negative signs.

Order of Operations with Integers

The Question is...

(+5) x (-3) + (-6) ÷ (+3)=

The first thing that you need to know is that the order of operations is BEDMAS. BEDMAS means brackets, exponents and the brother sister pairs division and multiplication. The other pair is adding and subtraction. That is the order that they should be done in but with the brother and sister ones you go just from left to right.

Because there is no brackets other than the ones around one number and there is no exponents the first thing you will do is the multiplication of (+5)x(-3). To get (-15), so then the new question is (-15)+(-6)÷(+3)=. Then you have to divide (-6) by (+3). The answer is (-2) and the new question is (-15)+(-2)=. All you have to do then is to add them together to get the answer of (-17).