1. How to use patterns to multiply with 9 as a factor.
Today we will learn…
How to use patterns to multiply with 9 as a factor.
5-2: 9 as a factor
Vocabulary
Factor
Product
Multiple

2. 3 X 5 = 15 Vocabulary Review factors product
Multiplication is an operation that gives the total number when you join equal groups.
3 X 5 = 15
factors
product
What do we call the numbers you are multiplying?
What is the answer to a multiplication problem called?

3. Let’s say the first 12 multiples of 9 together:
Vocabulary
Multiples: All of the numbers that you say when you skip count by a given factor.
Let’s say the first 12 multiples of 9 together:
9, 18, 27, 36, 45, 54, 63, 72, 81, 99, 90, 108
Counting by 9’s song

4. What patterns do you see?
Think on your own
Now, use skip counting to write the x9 facts on a whiteboard with your partner.
9x0=0
9x1=9
9x2=18
9x3=27
9x4=36
9x5=45
9x6=54
9x7=63
9x8=72
9x9=81
9x10=90
9x11=99
9x12=108
What patterns do you see?

5. The x9 hand trick is another way to solve x9 facts!
Hand Trick Video

6. (record on whiteboards)
Think as a group
(record on whiteboards)
Maria bought 4 packages of bottled water. There are 9 bottles in each package. How many bottles did she buy?
Decide how to solve the problem
Write an explanation of your thoughts
You can use words, pictures, numbers, and symbols to help you explain your answer.

7. Think with your partner (record on a whiteboard)
The bookstore is selling books for 9 dollars each. Ryan wants to buy 6 books. How much will this cost?
Decide how to solve the problem
Write an explanation of your thoughts
You can use words, pictures, numbers, and symbols to help you explain your answer.

8. Problem Solving
Carefully read the problem.
Underline the question.
[Bracket] important words and numbers. 
Eliminate unnecessary information.  
Solve and check your work.
Melissa bought 2 t-shirts for $9.00 each. If she had $32.00 in her purse, how much money does she have left?
Decide on a strategy to solve the problem (repeated addition, equal groups, skip counting, make an array)
Start writing your explanation by explaining each step using the word because.
Write a sentence stating the answer to the question with a correct label.