1. Lesson Study Group B February 2012
FUN with Functions!
Lesson Study Group B
February 2012

2. Objectives
I will be able to use a function table to write an equation.
I will be able to use the equation to complete the missing values in the function table.
Algebra and FUNCTIONS 1.5

3. Prior Knowledge 7 9 6 3 4 1 Finding Patterns
Find a pattern between the yellow column and the blue column.
It is not a pattern until you have checked 3 rows! 4 1 7 9 6 3
Teacher Modeling
The pattern is subtract 3
The pattern is

4. Prior Knowledge 3 5 9 12 15 27 36 Finding Patterns
Find a pattern between the yellow row and the blue row.
The pattern is multiply by 3
The pattern is
Ask: How do you prove it is a pattern? Choral: YOU HAVE TO CHECK THREE!
Where do I start to find my pattern? TPS/WB
Then find pattern: display on WB 3 5 9 12 15 27 36

5. Prior Knowledge 1 8 2 36 9 24 6 16 4 Finding Patterns
Find a pattern between the yellow column and the blue column. 16 4 1 8 2 36 9 24 6
The pattern is divide by 4
The pattern is
What do you compare? Blue to yellow or yellow to blue? Choral: Yellow to blue
Find pattern: WB (TWPS to explain)

6. Prior Knowledge 3 5 7 1 9 2 Finding Patterns
Find a pattern between the yellow row and the blue row.
The pattern is add 2
The pattern is
Find pattern: WB: Be ready to share: Random Select 3 5 7 1 9 2

7. What is a Function? x 8 y
+ 4 12
Teacher Talk
A function is a rule, that for every value of x (input) gives exactly one value of y (output).

8. What is a Function? x 7 y
+ 4 11
Students read definition to their partners.
Explain what it means to partners (call on student with correct answer after listening to their discourse).
A function is a rule, that for every value of x (input) gives exactly one value of y (output).

9. x + 5 = y y = x + 5 Functions is the input (x) + 5 is the rule
In the incomplete equation = ___
is the input (x)
+ 5 is the rule
Teacher Talk
x + 5 = y
_____ is the output (y)
y = x + 5

10. What is a Function Table?x y 4 1 8 2 36 9 24 6
A function table is a way of organizing values.
Now you can find a pattern between an x value and a y value to write an equation. a a a a a a
Ask: How many rows of x and y do we need to prove that our pattern is accurate? (Show me on fingers) a a

11. Connecting a Function to its Table
Let’s imagine this equation
+ 5 = ___
The input is a number going in.
+ 5 is the rule
x (input)
y (output)
The output is the result of applying the rule ( + 5)
Write in some values for x and y to show students.

12. Steps for Writing an Equation
Step 1: Find a pattern
Step 2: Identify the rule
Step 3: Write an equation by adding x and y to the rule.

13. Writing an equation 5 15 9 27 12 36 x y x y y = 3x The rule is… · 39 27 12 36 x y
The rule is…
· 3
= ___
Ask: Do we start with the x column or the y column?
Students: Find pattern.
Write rule. (WB)
Teacher: Model writing equation
3x = y
y = 3x

14. Writing an equation 7 4 9 6 3 x y x y The rule is… - 3 = ___ y = x - 3x y
The rule is…
- 3
= ___
Students find rule.
Think to yourself: What is going to be with the rule?
Students self-check as teacher models writing equation
y = x - 3

15. Writing an equation x 5 7 1 y 9 2 3 x y + 2 The rule is… = ___1 y 9 2 3 x y
Students find rule.
Think to yourself: What is going to be with the rule?
Students self-check as teacher models writing equation
+ 2
The rule is…
= ___
y = x + 2

16. Writing an equation x 25 35 10 5 y 7 2 1 x y ÷ 5 The rule is… = ___
Students find rule.
Students: Write the equation using the rule: WB
1-16KIM
÷ 5
The rule is…
= ___
y = x ÷ 5

17. Steps to Completing a Function Table
Steps for Writing an Equation
Steps to Completing a Function Table
Step 1: Find a pattern
Step 2: Identify the rule
Step 3: Write an equation by adding x and y to the rule.
Step 4: Use the x value to calculate
the y value.
DENISE and CRAIG Start
Have students read steps 1-3
Then reveal step 4

18. Function Tables 5 10 7 12 15 13 18 15 20 17 22 The rule is: = = ___
= ___
+ 5 x y x y 5 10 7 12 15
Students on WB: Find pattern and write rule on WB (show me)
Turn into equation on WB (show me)
I Do… Choral response starting w/#13
With #20 teacher model how to work backwards INVERSE OPERATION 13 18 15 20 17 22

19. Function Tables 6 18 12 5 15 4 7 21 3 9 10 30 The rule is: = ___ = · 3
= ___ =
· 3 x y x y 6 18 12 5 15 4
Students on WB: Find pattern and write rule on WB (show me)
Turn into equation on WB (show me)
Students: Think Pair Share on #12
#30 on WB 7 21 3 9 10 30

20. Function Tables y = x - 6 18 12 10 4 20 14 9 3 16 10 6 Equation
x – 6 = y
y = x - 6
Equation x y 18 12 10 4 20 14
We Do – White Boards Write equation (show me)
Fill in empty spaces on table TWPS (show me) 9 3 16 10 6

21. Function Tables y = x - 4 Equation x – 4 = y x 6 9 11 15 40 y 2 7 1620 5 36
We Do – White Boards Write equation (show me)
Fill in empty spaces on table TWPS (show me)

22. Function Tables y = x ÷ 4 20 5 8 2 4 1 24 6 12 3 28 7 Equation
x ÷ 4 = y
y = x ÷ 4
Equation x y 20 5 8 2 4 1
We Do – White Boards Write equation (show me)
Fill in empty spaces on table TWPS (show me) 24 6 12 3 28 7

23. Function Tables y = x · 6 3 18 5 30 9 54 6 36 7 42 Equation x ·6 = y x
We Do – White Boards Write equation (show me)
Fill in empty spaces on table TWPS (show me) 9 54 6 36 7 42

24. Function Tables y = x +9 Equation x + 9 = y x 2 22 13 8 y 11 17 16 9 7y 11 17 16 9 7 31 22
We Do – White Boards Write equation (show me)
Fill in empty spaces on table (show me)
We Do – White Boards Which to remove and which to keep?

25. Function Tables y = x ÷ 8 32 4 24 3 16 2 88 56 7 48 6 Equation
x ÷8 = y
y = x ÷ 8
Equation x y 32 4 24 3 16 2 11
We Do – White Boards Write equation (show me)
Fill in empty spaces on table (show me)
We Do – White Boards Which to remove and which to keep? 88 56 7 48 6

26. CST Released Question y = x + 9 y = x – 9 y = 9x y =
Which equation could have been used to create this function table?
y = x + 9
y = x – 9
y = 9x
y = x y 9 81 2 18 4 36 11 99
Think write pair share (WB) Random select for justifying
Justify your answer

27. Number of Family Members
Word Problem
Choose the number to complete the function table to find how much 9 tickets will cost. $8
$102
$136
$153
Number of Family Members
Total Cost for Tickets 1
$17 2
$34 5
$85 9
Think write pair share (WB) Random select for justifying
Justify your answer

28. Which table represents values of x and y such that y = x + 7?1 8 4 10 x y 2 9 3 11 C. x Y 9 2 6 1 x y 4 11 2 9
Think write pair share (WB) Random select for justifying B. D.
Justify your answer

29. Objectives
I will be able to use a function table to write an equation.
I will be able to use the equation to complete the missing values in the function table.

30. Ticket Out the Door! QUIZ You Rule!
Complete quiz from today’s lesson with the following information:
Rule
Equation
Explanation
Complete function table
Create your own function table with the following information:
Rule
Equation
Completed Table:
must have an x and a y
include at least 4 rows of numbers
Write a real life situation to go with your table
15-28 DENISE/CRAIG

31. Guess My Rule! Input Partner A Output Partner B Input Partner A Output
Partner B pulls a card
Partner A pulls a card
Input
Partner A
Output
Partner B
Input
Partner A
Output
Partner B