# Topic 3 Multiplying Whole Numbers

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TOPIC THREE Multiplying Whole Numbers

****It is extremely important to learn your facts****

Lesson One

Objective:  identify and apply the Commutative, Associative, Identity, and Zero Properties of Multiplication

Vocabulary:

Commutative Property of Multiplication - You can multiply two numbers in any order and get the same product.
7 x 5 = 5 x 7

***  You may have heard this as a turn around or a flip.    However, now that you are in fifth grade you need to use the proper terminology.

Associative Property of Multiplication - You can change the groupings of three or more factors and get the same product.

(6 x 2) x 3 = 6 x (2 x 3)
12 x 3 = 6 x 6
36 = 36

Identity Property of Multiplication - Any number multiplied by 1 is that number.

6 x 1 = 6                                     1 x 45 = 45                             578 x 1 = 578

Zero Property of Multiplication - Any number multiplied by 0 is 0.

7 x 0 = 0                                    0 x 56 = 0                              698 x 0 = 0

Lesson Two

Objective:  mentally compute products of whole numbers using place value patterns and the properties of multiplication

Vocabulary:

Factors:   numbers that are multiplied together

Product:  answer to a multiplication problem

Multiple:  a product of a whole number and another whole number

Knowing 3 x 7 can help you solve 30 x 7 and 300 x 7
3 x 7 = 21
30 x 7 = 210
300 x 7 = 2100

You can use the Associative Property to solve more difficult problems:

50  x  32  x 2                                                             4  x  33  x  25
50  x  2  = 100                                                            4  x 25  = 100
100  x 32  = 3200                                                      100  x 33  = 3300

Lesson Three

Objective:  use estimating to determine the product

Vocabulary:    underestimate - when you estimate low
overestimate - when you estimate high

24  x  39 =
Estimate 24 to 20 and 39 to 40
20  x  40  = 800

75  x  28
80  x  30  = 2400

97 x 15
100  x 15
1500

Lesson Four

Objective:  use exponential notation

Vocabulary:    base - the number to be multiplied
exponent  - the number that tells how many times the base is used as a factor
expanded form - 5 x 5 x 5
standard form - 125 (answer to the problem)
3
exponential notation   5

You can also read these to the second, third, fourth power......etc.
The second power is squared.
The third power is cubed.

Lesson Five

Objective:  use the Distributive Property to simplify expressions and solve equations.
Think about how you can break apart numbers and "Distribute" them.

7 x 86                                                            132 x 8
( 7 x 80) + ( 7 x 6)                                          (100 x 8) + ( 30 x 8) + ( 2 x 8)
560 + 42                                                            800      +     240    +   16
602                                                                                    1056

Lesson Six

Objective:  multiply multi-digit numbers by one digit numbers

22
567
x  3
1701

Lesson Seven and Eight

Objective: multiply multi-digit numbers by multi-digit numbers

36                                                                            472
x23                                                                            x36
108                                                                          2562
+720                                                                       +12810
928                                                                       15372

Lesson Nine

Objective:  use diagrams and write equations to solve problems

Assessment - What do you need to Know?????