Lesson: 4-6 Arithmetic Sequences

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Lesson Objective

SWBAT identify and describe arithmetic sequences and write an equation for the nth term.

Lesson Plan

Teacher: Hall
Course:    8th Math
Date: Nov 16, 2009
SWBAT identify arithmetic sequences and find the nth term of a sequence
Unit Title: 4
Objective Number:
Materials: do now, cc, packet, transparencies, ex, hw
Vocabulary: arithmetic, common difference, sequence
Do now:
Purpose of the do now: 
xCumulative Review _____________
â–¡Activate Prior Knowledge
â–¡Introduce Lesson
â–¡Other ___________________
Total Recall / Hook: How will you transition from the Do Now into today’s objective? How will you tie your recall to the importance of today’s objective?
 Today is all about patterns – and our brains are genetically wired to see patterns. Any time we look at a set of numbers, we are always looking for patters.
1-what is 110% of 200? (220)
2-what is 1.25 times 8? (10)
3-what is the product of 400 and 200 ? (80,000)
4-what is the product of 9 and 15? (135)
5-how many quarters are in $9.75? (39)
6-how many inches are in ½ yard? (18)
7-what is the volume of a cube with a side length of 5 inches? (125)
8-what is the area of a triangle with a base of 3 inches and a height of 40 inches? (60 sq in)
9- point A is in the first quadrant – if it is rotated 90 degrees clockwise, what quadrant will A’ be in? (fourth)
10- solve: 6x – 3 = 33 (6)
Agenda: Outline of your lesson
  1. Do now (5 )
  2. Cranium Crunch (5 )
  3. Review CC/DN (10)
4.      Mental Math (5 )
5.      Hook (5 )
6.      INM1 (5 )
7.      GP1 (10 )
8.      CFU1 (2 )
9.      IP1 (10 )
10. INM2 (5 )
11. GP2 (10 )
12. CFU2 (3 )
13. IP2 (25 )
14. Share (5 )
15. Exit Ticket (10 )
16. Closing (5 )
Intro to NM
Go through vocabulary and an example of a sequence – what makes a sequence arithmetic? (most sequences have patterns, but an arithmetic sequence is a particular type of patter – where there is a common difference – you add or subtract the same number to get from one term to the next)
Model A-D:
What’s the pattern?
How do you get from one number to the next?
Is it the same for each term in the sequence?
Is it arithmetic? Why or why not?
Raise your hand if you could tell me the next two numbers… (don’t take answers)
Example 2:
How do you know it’s an arithmetic sequence?
How can you find the next three terms?
Stretch: how might you find the 20th term?
Now You Try:
Is it arithmetic? How do you know?
What is the common difference? Positive or negative?
What is the next term? After that?
Key questions to ask during GP: (Question Script) 
IP 1 
In your notebooks: IP1: p168 #1-4; #13-19 (odd); 35, 39, GOLD 46-47
Intro to NM
Now, of course, we are going to make it algebra!
We can represent sequences using symbols – and just like always, this algebra is going to help use find a rule that will help us extend the pattern, and solve problems
Go through table and formula
Model Example 3
-          write equation, use equation, graph the results (have students do last few steps on their own)
-          how did we come up with the equation? why? (restate)
Now You Try: read it together, make sure they understand – let them solve on their own (optional: in partners)
Share out after 5 mins (give students an overhead) – then move on to IP
Key questions to ask during GP: (Question Script) 
-          is the sequence arithmetic? how do you know?
-          what equation represents this sequence? why? how can we check if our equation is correct?
-          why is this equation useful? how can we use it?
Key questions to check for understanding before IP (Last three questions you will ask) 
Independent Practice Activity:
IP2: page168-170: #7-11, 20-21, 27, 37, 44, 45; Gold 48, 50, 51, 52
Closure: How will you close the lesson? 
Share out answers from IP
Exit ticket
Assessment: How will you assess mastery of the objective?
  •     Exit ticket
Anticipated Challenges
Reflection: Students understood how to use the formula, but I didn’t do a very good job of explaining WHY the formula works and how it connects to slope-intercept form linear equations.

Lesson Resources

4 6 HW  
4 6 DN  
4 6 packet  
4 6 EX  


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