Multiplication
Properties
Do you remember these Properties of Addition?
Commutative Property of Addition
The numbers move around
a + b = b + a
Associative Property of Addition
Grouping with parentheses
(a + b) + c = a + (b + c)
Identity Property of Addition
The identity of the problem does not change
a + 0 = a
In multiplication, you will see these
same properties, plus 2 more…
Five Properties of Multiplication
These are the basically the same as
addition
Commutative
Associative
Identity
These belong to multiplication only
Zero
Distributive
Let’s review the addition
properties— from the
multiplicative perspective…
Multiplicative (Do you see most of the word “multiply” in this word?
Property #1
The Commutative Property
of Multiplication
The Commutative Property
Background
The word commutative comes from the
verb “to commute.”
Commuting means changing, replacing,
exchanging, switching places, trading
places
People who travel back and forth to
work are called commuters.
The Commutative Property
A • B = B • A
Here is another example…
3 groups of 5 = 5 groups of 3
=
15 kids
=15 kids
3 x 5 5 x 3=
What commutative means to
multiplication…
3 groups of 5 = 5 groups of 3
3 • 5 = 5 • 3
a • b = b • a
Remember… in
Lesson 1-11 we said
that the word “of”
means multiply
Property #2
The Associative Property
of Multiplication
The Associative Property
Background
The word associative comes from the
verb “to associate.”
Associate means connected, joined, or
related
People who work together are called
associates.
They are joined together by business, and
they have to talk to one another.
A C
B
Here are three associates.
B calls A first He calls C
last
If he called C first,
then called A, would
it have made a
difference?
(The Role of Parentheses)
In math, we use parentheses to show groups.
In the order of operations, the numbers and
operations in parentheses are done first.
(PEMDAS)
So….
The Associative Property
(A  B)  C = A  (B 
C)
A C
B
A C
B
THEN THEN
The parentheses identify which two associates talked first.
Property #3
The Identity Property
of Multiplication
The Identity Property
I am me!
You cannot change
My identity!
One is the only number
you can multiply
something by and see no
change.
Identity Property of Multiplication
a x 1 = a
x 1 =
Identity Property of Multiplication
a x 1 = a
x 1 =
x 1 =
x 1 =
These are 3 of the Properties of Multiplication
Commutative Property of Multiplication
The numbers move around
a • b = b • a
Associative Property of Multiplication
Grouping with parentheses
(a • b) • c = a • (b • c)
Identity Property of Multiplication
The identity of the problem does not change
a • 1 = a
There are two more properties
which are unique to multiplication
The Zero Property
The Distributive Property
Property #4
The Zero Property of Multiplication
The Zero Property of Multiplication
This looks like a mixture of the identity
property of addition and the identity
property of multiplication…
Be careful not to mix them up!
The Zero Property
Any time you multiply a number by zero,
your answer is zero! If I have 2
pockets with NO
money in them,
then I have NO
money!
2 • 0 = 0
The
Property #5
The Distributive Property
of Multiplication
The Distributive Property
Background
The word distributive comes from the
verb “to distribute.”
Distributing refers to passing things out or
delivering things to people
The Distributive Property
a(b + c) = (a • b) + (a • c)
A times the sum of b and c = a times b plus a times c
Let’s plug in some numbers first.
Remember that to distribute means delivering items, or handing them out.
Here is how this property works:
5(2 + 3) = (5 • 2) + (5 • 3)
5(2 + 3) = (5 • 2) + (5 • 3)
You went to two houses on one street and three houses on a different street.
Every family bought 5 items!
You went to two houses on one street and three houses on a different street. Every family bought 5 items!
You have sold many items for the RCMS fundraiser!
You will be distributing 5 items to each house.
1
2
3
4
5
5(2 + 3) = (5 • 2) + (5 • 3)
You distributed (delivered) these all in one trip.
There are (2+3) five houses all together.
You need to deliver 5 gifts to each house.
You need to put 25 items on your wagon at
one time.
5 items x 5 houses = 25 items all together
5(2 + 3) = (5 • 2) + (5 • 3)
You distributed your items in
two trips (+).
On the first trip you
distributed 5 items to each of
2 houses (5 x 2 = 10).
On the second trip you
distributed 5 items to each of
3 houses (5 x 3 = 15).
That means you distributed
(delivered) 10 items plus 15
items. That makes 25 items
altogether.
and
10
15
+
25
The Distributive Property
DISTRIBUTION CENTER
Make 1 trip. You have 5 houses. You
need to bring 5 items to each house.
You need 25 items on your wagon.
5(2 + 3)
The Distributive Property
DISTRIBUTION CENTER
Make 2 trips. You have 2 houses for
your first trip and you need to bring 5
items to each house. You have 3
houses on your second trip and need
to bring 5 items to each house. When
your second trip is over, you will have
distributed 25 items.
(5 • 2) + (5 •3)
How do I tell the properties apart?
Commutative
Numbers switch places
Associative
Parentheses on both sides
Only multiplication on each side
Identity
Multiply by 1
Zero Property
Multiply by zero
Distributive
Parentheses on each side
One side has a multiplication sign AND a plus sign
Let’s practice !
Look at the problem.
Identify which property it represents.
4(5 + 6) = (4 • 5) + (4 • 6)
The Distributive Property
of Multiplication
•3 numbers on one side—4 on the other
•Multiplication AND addition
•3 sets of parentheses
987 • 1 = 987
The Identity Property
of Multiplication
•Times 1
3 • 0 = 0
Zero Property of Multiplication
•Times zero
(1 • 2) • 3 = 1 • (2 • 3)
The Associative Property of
Multiplication
•Same 3 numbers
•Multiplication only
•2 sets of parentheses
6 • 11 = 11 • 6
The Commutative Property
of Multiplication
•Same 2 numbers
•Numbers switched places
9 • 7 = 7 • 9
The Commutative Property
of Multiplication
•Same 2 numbers
•Numbers switched places
12 • 0 = 0
Zero Property of Multiplication
•Times zero
(9 • 8) • 7 = 9 • (8 • 7)
The Associative Property of
Multiplication
•Same 3 numbers
•Multiplication only
•2 sets of parentheses
9(8 + 7) = (9 • 8) + (9 • 7)
The Distributive Property
of Multiplication
•3 numbers on one side—4 on the other
•Multiplication AND addition
•3 sets of parentheses
9 • 1 = 9
The Identity Property
of Multiplication
•Times 1
a • 1 = a
The Identity Property
of Multiplication
a • b = b • a
The Commutative Property
of Multiplication
A
(a + b) + c = a + (b + c)
The Associative Property
of Multiplication
C
B
a • 0 = 0
The Zero Property
of Multiplication
a(b • c) = (a • b) + (a • c)
The Distributive Property
of Multiplication

PROPERTIES OF MULTIPLICATION

  • 1.
  • 2.
    Do you rememberthese Properties of Addition? Commutative Property of Addition The numbers move around a + b = b + a Associative Property of Addition Grouping with parentheses (a + b) + c = a + (b + c) Identity Property of Addition The identity of the problem does not change a + 0 = a
  • 3.
    In multiplication, youwill see these same properties, plus 2 more…
  • 4.
    Five Properties ofMultiplication These are the basically the same as addition Commutative Associative Identity These belong to multiplication only Zero Distributive
  • 5.
    Let’s review theaddition properties— from the multiplicative perspective… Multiplicative (Do you see most of the word “multiply” in this word?
  • 6.
    Property #1 The CommutativeProperty of Multiplication
  • 7.
    The Commutative Property Background Theword commutative comes from the verb “to commute.” Commuting means changing, replacing, exchanging, switching places, trading places People who travel back and forth to work are called commuters.
  • 8.
  • 9.
    Here is anotherexample…
  • 10.
    3 groups of5 = 5 groups of 3 = 15 kids =15 kids 3 x 5 5 x 3=
  • 11.
    What commutative meansto multiplication… 3 groups of 5 = 5 groups of 3 3 • 5 = 5 • 3 a • b = b • a Remember… in Lesson 1-11 we said that the word “of” means multiply
  • 12.
    Property #2 The AssociativeProperty of Multiplication
  • 13.
    The Associative Property Background Theword associative comes from the verb “to associate.” Associate means connected, joined, or related People who work together are called associates. They are joined together by business, and they have to talk to one another.
  • 14.
    A C B Here arethree associates. B calls A first He calls C last If he called C first, then called A, would it have made a difference?
  • 15.
    (The Role ofParentheses) In math, we use parentheses to show groups. In the order of operations, the numbers and operations in parentheses are done first. (PEMDAS) So….
  • 16.
    The Associative Property (A B)  C = A  (B  C) A C B A C B THEN THEN The parentheses identify which two associates talked first.
  • 17.
    Property #3 The IdentityProperty of Multiplication
  • 18.
    The Identity Property Iam me! You cannot change My identity!
  • 19.
    One is theonly number you can multiply something by and see no change.
  • 20.
    Identity Property ofMultiplication a x 1 = a x 1 =
  • 21.
    Identity Property ofMultiplication a x 1 = a x 1 = x 1 = x 1 =
  • 22.
    These are 3of the Properties of Multiplication Commutative Property of Multiplication The numbers move around a • b = b • a Associative Property of Multiplication Grouping with parentheses (a • b) • c = a • (b • c) Identity Property of Multiplication The identity of the problem does not change a • 1 = a
  • 23.
    There are twomore properties which are unique to multiplication The Zero Property The Distributive Property
  • 24.
    Property #4 The ZeroProperty of Multiplication
  • 25.
    The Zero Propertyof Multiplication This looks like a mixture of the identity property of addition and the identity property of multiplication… Be careful not to mix them up!
  • 26.
    The Zero Property Anytime you multiply a number by zero, your answer is zero! If I have 2 pockets with NO money in them, then I have NO money! 2 • 0 = 0 The
  • 27.
    Property #5 The DistributiveProperty of Multiplication
  • 28.
    The Distributive Property Background Theword distributive comes from the verb “to distribute.” Distributing refers to passing things out or delivering things to people
  • 29.
    The Distributive Property a(b+ c) = (a • b) + (a • c) A times the sum of b and c = a times b plus a times c Let’s plug in some numbers first. Remember that to distribute means delivering items, or handing them out. Here is how this property works: 5(2 + 3) = (5 • 2) + (5 • 3)
  • 30.
    5(2 + 3)= (5 • 2) + (5 • 3) You went to two houses on one street and three houses on a different street. Every family bought 5 items! You went to two houses on one street and three houses on a different street. Every family bought 5 items! You have sold many items for the RCMS fundraiser!
  • 31.
    You will bedistributing 5 items to each house. 1 2 3 4 5
  • 32.
    5(2 + 3)= (5 • 2) + (5 • 3) You distributed (delivered) these all in one trip. There are (2+3) five houses all together. You need to deliver 5 gifts to each house. You need to put 25 items on your wagon at one time. 5 items x 5 houses = 25 items all together
  • 33.
    5(2 + 3)= (5 • 2) + (5 • 3) You distributed your items in two trips (+). On the first trip you distributed 5 items to each of 2 houses (5 x 2 = 10). On the second trip you distributed 5 items to each of 3 houses (5 x 3 = 15). That means you distributed (delivered) 10 items plus 15 items. That makes 25 items altogether. and 10 15 + 25
  • 34.
    The Distributive Property DISTRIBUTIONCENTER Make 1 trip. You have 5 houses. You need to bring 5 items to each house. You need 25 items on your wagon. 5(2 + 3)
  • 35.
    The Distributive Property DISTRIBUTIONCENTER Make 2 trips. You have 2 houses for your first trip and you need to bring 5 items to each house. You have 3 houses on your second trip and need to bring 5 items to each house. When your second trip is over, you will have distributed 25 items. (5 • 2) + (5 •3)
  • 36.
    How do Itell the properties apart? Commutative Numbers switch places Associative Parentheses on both sides Only multiplication on each side Identity Multiply by 1 Zero Property Multiply by zero Distributive Parentheses on each side One side has a multiplication sign AND a plus sign
  • 37.
    Let’s practice ! Lookat the problem. Identify which property it represents.
  • 38.
    4(5 + 6)= (4 • 5) + (4 • 6) The Distributive Property of Multiplication •3 numbers on one side—4 on the other •Multiplication AND addition •3 sets of parentheses
  • 39.
    987 • 1= 987 The Identity Property of Multiplication •Times 1
  • 40.
    3 • 0= 0 Zero Property of Multiplication •Times zero
  • 41.
    (1 • 2)• 3 = 1 • (2 • 3) The Associative Property of Multiplication •Same 3 numbers •Multiplication only •2 sets of parentheses
  • 42.
    6 • 11= 11 • 6 The Commutative Property of Multiplication •Same 2 numbers •Numbers switched places
  • 43.
    9 • 7= 7 • 9 The Commutative Property of Multiplication •Same 2 numbers •Numbers switched places
  • 44.
    12 • 0= 0 Zero Property of Multiplication •Times zero
  • 45.
    (9 • 8)• 7 = 9 • (8 • 7) The Associative Property of Multiplication •Same 3 numbers •Multiplication only •2 sets of parentheses
  • 46.
    9(8 + 7)= (9 • 8) + (9 • 7) The Distributive Property of Multiplication •3 numbers on one side—4 on the other •Multiplication AND addition •3 sets of parentheses
  • 47.
    9 • 1= 9 The Identity Property of Multiplication •Times 1
  • 48.
    a • 1= a The Identity Property of Multiplication
  • 49.
    a • b= b • a The Commutative Property of Multiplication
  • 50.
    A (a + b)+ c = a + (b + c) The Associative Property of Multiplication C B
  • 51.
    a • 0= 0 The Zero Property of Multiplication
  • 52.
    a(b • c)= (a • b) + (a • c) The Distributive Property of Multiplication