Commutative Property
According to the Commutative Property, what can I do to my factors?
Change the order
Flip flop them
The Associative Property says that when I multiply 3 numbers . . .
the grouping does not matter
I can multiply them in any order
All numbers multiplied by 1 equal...
that number
example: 743 x 1 = 743
20 x 6
120
Estimate by rounding.
47 x 4
50 x 4 = 200
Use the commutative property to write this another way:
3 x 7
7 x 3
(6 x 20) x 5 = 6 x (20 x _____)
Fill in the blank.
5
Any number multiplied by 0 equal...
0
40 x 9
360
Estimate.
412 x 87
400 x 90 = 36,000
53 x 6 = 6 x ______
53
5 x (40 x 9) =
What do the parenthesis mean?
Do that first
542 x 1 =
542
60 x 70
4,200
Estimate.
691 x 502 =
700 x 500 = 350,000
932 x 15 = 13,980.
What is the product of 15 and 932?
13,980
(9 x 3) x 5 = 135
What is the product of 9 x (3 x 5) ?
135
Lucy multiplied a number by 0. What was the product?
0
300 x 50
15,000
Joey has 12 boxes. Each box has 27 video games in it. About how many video games does Joey have?
10 x 30 = 300 video games
Dan has 4 shelves. He has 10 books on each shelf.
Judy has 10 shelves. She has 4 books on each shelf.
Who has more books?
They have the same number of books.
4 x 10 = 40
10 x 4 = 40
4 x 25 x 27
To get the correct answer, which factors do I need to multiply first?
It does not matter.
No, it has to be that number.
Example 67 x 1 = 67
67 = 67
Kelly has 40 boxes. Each box has 700 greeting cards. How many greeting cards does she have?
28,000 cards
Mrs. Carter ordered new supplies for Memorial Hospital. Each electronic thermometer costs $19. About how much will it cost to purchase 48 thermometers?
20 x 50 = $1,000