Julius' scribe post

Julius' scribe post

Multiplying Integers

first we learned to multiply two positives together. To multiply positives you multiply them. But you have to show your work.

For example:

(+3)x(+4)= +12

to show your work you have to write out: (number) groups of (number)

(+3)x(+4)=+13

3 groups of 4

You also have to model the question. To model you must have a certain number of groups containing a certain number of positives/negatives. But it is not a group unless you circle the groups. Then show that they are arriving

(++++) (++++) (++++)<-------

Multiplying negatives

To multiply negatives you do the same thing except with a negative.

For example:

(2)x(-3)= -6

2 groups of negative 3

(---) (---)<----

If the first number is a negative then the words start with remove

(-4)x(3)= -12

remove 4 groups of 3

to do this we need to have zero pairs

--- --- --- ---

(+++) (+++) (+++) (+++)

then make 4 groups of 3 positives. And then show that the positives/negatives are going away by making a arrow pointing away from the groups.

(+++)----> (+++)-----> (+++)-----> (+++)---->

f you are still feeling confused here is a video

feel free to criticize and correct me 

Gabby's scribe post #2

Multiplying integers: Positives and Negatives

Today during class we learned how to multiply integers! 

Multiplying positives:

We started off with a very simple question and it was:

(+4) x (+3)= 12

Figuring out the answer is simple if you write the question down first. In this case the question in L.A form would be 4 groups of 3. This means: 3+3+3+3= 12, this is called repeat addition (skip count).

Even if this is a simple question we have to model the question to show our work.

Remember to group your integer tiles!

Lets practice on one more multiplying positive integers question.

(2)x(3)=6

2 groups of 3. 3+3=6

                                                                   

Multiplying with negative and positive integers:

(-4)x(3)=

To make this question easier you must write it down in words.

Negative 4 remove groups of positive 3. To remove something that isn't there you must use zero pairs, in this case you have to use 12 (=4x3).

Positive: Blue
Negative: Red

Now that you have your 4 groups of 3, like in what we wrote later we have to "remove 4 groups of positive 3".

Negative x Negative multiplying.

 (-2)x(-3)= +6

 Negative 2 remove groups of negative 3= positive 6

                                                      

Remove 2 groups of negative 3:

video: http://www.youtube.com/watch?v=47wjId9k2Hs