Grades 8-12
Mathematics
Geometry
Standard 3

Students construct and judge the validity of a logical
argument, and this includes giving counter examples
to disprove a statement.


 
Resources
Lesson Plans
Assessments

Geometry Larson/
Boswell/Stiff, 1995, 
D. C. Heath and Company 

Section References

2.1 Exploring Patterns 

2.4 Conditional Statements 

2.5 Resoning with Properties form Algebra 

2.6 Deductive Reasoning 

Software 

Tabletop, Broderbund Software, Inc. 1995 
cd mac/windows 

Specific Textbook 
Web Sites

http://www.glencoe.com/
sec/math/prealg/mathnet/

http://www.eduplace.com/
links/

http://www.eduplace.com/

http://www.hmco.com/
college/mathematics/
index.html

http://www.mcdougallittell
.com/

http://www.hmco.com/

http://www.SRA-4KIDS.com/

General Math 
Reference Sites

http://www.learner.org/
sami/view-category.php3
?category=math

http://www.score.k12.ca.us/

http://henson.austin.apple
.com/edres/curric.shtml

http://school.discovery.com/
schrockguide/index.html

http://www.EDsOasis.org/

http://www.math.com/

http://www.nea.org/grants/
free.html

http://www.wcom.com/
marcopolo/

http://www.udel.edu/sine/

http://dewey.chs.chico.k12
.ca.us/math.html

Free Stuff

http://www.nea.org/
grants/free.html

State/National Math 
Ed Organizations

http://www.nctm.org/

http://www.cde.ca.gov/

Calif. Dept. of Ed. Standards, Assessment, Ed. Reference.

Calculuator Reference Site

http://www.ti.com/
calc/docs/calchome.html



Previously Published Data

1.) Students will construct universal statements. 


2.) Students will construct existence statements. 
3.) Students will construct counter examples to disprove universal and existence statements. 
4.) Students will find uses of logical or illogical statements in advertisements in magazines, newspapers, and TV. For example: if you wear Nike shoes, then you will play basketball as well as Michael Jordan; if you smoke, then you will get lung cancer.

Example:

A Deli held a drawing. The customers dropped their business cards in a box, and the owner pulled out one winning card each weekday. No customer was employed by the same firm, no winner won twice, and no winners received the same prize. From the information provided, determine the customer who won each weekday, the firm for which each customer works, and the prize the customer won.

Use the following information:

Customer:

Al, Cissy, Deb, Joe, and Tom

Weekday:

Monday, Tuesday, Wednesday, Thursday, and Friday

Prize:

Breakfast, Desserts, Salads, Sandwiches, and Soups



Previously Published Data

1.) Students will distinguish between universal and existence statements. 


2.) Students will construct counterexamples for universal statements. 
3.) Students will construct counterexamples for existence statements.