Title
Arithmetic and Geometric Sequences
Skill
Making a Basic Argument
EBA Activity
Argument Four Corners. .
Claims
The following claims may be used for this activity:
 The growth of a new student club from year to year will be best
modeled by a _________________ sequence.
 The growth of members on the next big social networking site after
Facebook will be best modeled by a _________________ sequence.
 The growth of the number of residents in a new town will be best
modeled by a __________________ sequence.
[Fill in the blank with arithmetic or geometric]
Procedure
1. In pairs students are provided with the activity’s claims, for which they
design projected amounts that either follow an arithmetic or geometric
sequence. From these projected amounts students will create warrants
justifying their claims.
2. Proceed with a standard argument Four Corners.
Timing/Pacing



This lesson will take place early on in this unit after students learned
about arithmetic sequences and on the day they learn about geometric
sequences. Students should be able to find the difference and quotient
between two numbers. After this lesson students will learn about
partial sums.
This activity will take 10 minutes.
This activity should be used in the middle of class after students learn
about the difference between geometric and arithmetic sequences. After
this activity students will practice finding the nth term in an arithmetic
sequence given the first term and the common difference.
Notes
For this activity students should provide warrants that explicitly state how and
why the example in the claim would grow by a common difference of ____ or
a common ration of ____ .
Follow Up
Activity
To add a writing component, follow up with a Mini Paragraph Writing Activity
using the textbook and the student’s projections as evidence.
Text
Standard Pre-Calculus Text.
Boston Debate League © 2012
Name:_____________________________________ Class: __________ Date:______________
Four Corners
Define:
Arithmetic Sequence
Geometric Sequence
Claim
The growth of a new student club from year to
year will be best modeled by an arithmetic
sequence.
Warrant- Reason for your stance.
Strongly
Agree
Disagree
Strongly
Agree
Disagree
The growth of members on the next big social
networking site after Facebook will be best
modeled by an arithmetic sequence.
Strongly
Agree
Disagree
Strongly
Agree
Disagree
The growth of the number of residents in a new
town will be best modeled by an arithmetic
sequence.
Strongly
Agree
Agree
Disagree
Strongly
Disagree
Speech Structure
“I _________________ with the claim
______________________________________________________________________.
My warrant for this stance is
______________________________________________________________________.”
Boston Debate League © 2012