Properties of Multiplication

Commutative Property:

The product doesn't change when you switch the order of the numbers being multiplied.

7 x 3 = 3 x 7

 x =

 x  

Zero Property:

Any number multiplied with a 0 equals 0.

24 x 0 = 0

 x 0 =

Identity Property:

Any number multiplied by 1 equals itself. 

2 x 1 = 2

  x 1 =  

1-2-3-Digit Multiplication

A digit is a number.  



is a single-digit number. 

9 x 9 = 81 
(single-digit multiplication)

is a two-digit number.

9 x 12 = 108
(1-digit x 2-digit multiplication)

12 x 12 = 144 

(2-digit x 2-digit multiplication)

is a three-digit number.

9 x 137 = 1,233
(1-digit x 3-digit multiplication)

12 x 137 = 1,644

(2-digit x 3-digit multiplication)

Estimating products

Estimating is when you solve multiplication problems by rounding the product to the greatest

place value.

Examples:

22 x 3 = ____ (estimate)

13 x  4 = _____(estimate)

(answer key)

Arrays and Equal Groups

An array is a group of objects organized into rows and columns.

Equal Groups can be used to show how multiplication works.

4 x 3 = 12 

Multiplication Riddle

Read and solve.

1. I can be multiplied by 4 to make 32.  I can be made by multiplying 2 x 4.  What number am I? 
2. If you multiply any of the numbers 1-9 by me, then you will get that number twice for an answer.  Multiply me by ten and you will get 110.  What number am I?

( answer key )

Multiplication Number Story

Read and solve.

1.  Cam Newton had 4 bags of footballs and each bag had 3 balls in it. How many footballs did Cam Newton have?

2.  Cam Newton threw 6 passes and made 4 yards each time. How many yards did he pass in total?

(answer key)

Multiples

Multiples are what you get after multiplying a number by an integer (not a fraction).



The following examples are multiples of 2:
0,2,4,6,8,10,12,14,16,18,20.......

this is because:
2 x 0 = 0
2 x 1 = 2
2 x 2 = 4 
2 x 3 = 6
(and so on)

The following examples are multiples of 5:
0,5,10,15,20,25,30,35,40.......

this is because:
5 x 0 = 0
5 x 1 =5
5 x 2 = 10
5 x 3 = 15
( and so on )

Extension facts

Extension facts are basic facts multiplied by a power of 10 (for example 10,100,1,000).

If 5 x 3 = 15,
then 50 x 3 = 150 and 500 x 3 = 1,500
and 5,000 x 3 = 15,000