Post on 17-Dec-2015
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Understanding Area Models for Multiplication
Understanding Area Models for Multiplication
Making Sense of Multiplication
Using any of the tools available at your table:
• Model 3 x 4
Meanings for multiplication
Repeated addition xxxx xxxx xxxx Array
xxxx
xxxx
xxxx Area Counting possibilities (I have 3 shirts and 2
pants, how many outfits?)3
With materials at your table, use an area model to show:
6 x 13
Using an area model to calculate 6 x 13:13
6
6 x 13 = 78
Making Sense of Multiplication
Using an area model to calculate 6 x 13:
10 3
6 6 x 10 6 x3
6 x 13 = 6 x (10 + 3) = (6 x 10) + (6 x 3) = 60 + 18 = 78
Making Sense of Multiplication
With materials at your table, use an area model to show:
12 x 26
Using an area model to calculate 12 x 26:
20 6
10
2
10 x 20 10x 6
2 x 20 2 x 6
Making Sense of Multiplication
12 x 26 = (10 + 2) (20 + 6) =
(10 x 20) + (10 x 6) + (2 x 20) + (2 x 6) =
200 + 60 + 40 + 12 = 312
9
Mixed Number Multiplication
How would you solve 2
1
4ÊÊ3
1
2?
Using a ruler and card, draw a rectangle that is by
inches, and find the total number of square inches.
Find your answer first by counting, then by multiplying.
Compare your answers--are they the same?
2
1
4
3
1
2
10
Mixed Number Multiplication
2
1
4ÊÊ3
1
2(2ÊÊ
1
4Ê)(3ÊÊ
1
2)
2
1
4
3
1
2
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Mixed Number Multiplication
2
1
4ÊÊ3
1
2(2ÊÊ
1
4Ê)(3ÊÊ
1
2)
2
1
4
3
1
2
Area model for fractionsfractionareamodel.gsp
12
1
2
1
3
A decimal example:
13