Department of Mathematics
Humboldt State University
Arcata, CA 95521
Office: BSS 346

EMAIL:flashman at
HSU:707-826-4950 (office/voice mail)

Illustrating Desargues' Theorem with a
            3-D Model.

At Forty-Second Annual State of Jefferson Mathematics Congress October 5, 2013

Professor Emeritus of Mathematics

Spring, 2017:
Jan./Feb. Visitor to Institute
for Mathematics and Education, University of Arizona.
April: Travel and visits to England. ATM and MA Conferences.

Find out about the Sensible Calculus Program (Older Version.)

Mapping Diagrams from A(lgebra) B(asics) to C(alculus) and D(ifferential) E(quation)s. A Reference and Resource Book on Function Visualizations Using Mapping Diagrams (In Development-Draft Version 12-2013)

Recent (and not so Recent - back to 2011) Stuff  [Papers/Presentations/etc.]

"The Role of Philosophy in Proof:Euclid's Proof of Proposition One.", Folsom Lake Math Club March 19, 2014 YouTube (30 minutes)
"A Sensible Approach to Calculus: Differential Equations, Estimation, and Modelling in The Fundamental Theorem.",Sacramento Valley Community College Mathematics Conference, March 15, 2014 (pdf)    YouTube Part I       YouTube Part II
"The Role of Philosophy in Proofs",HSU Colloquium, Feb 27, 2014 . YouTube (30 minutes)
"Making Sense of Series and Sequences in The First Calculus Course."JMM, Baltimore, MD. January 18, 2014
"Functions, Duality, and Mapping Diagrams" Folsom Lake College Math Club Presentation, Dec. 11, 2013, Folsom, CA.
"Visualizing Linearity:Alternatives to Lines and Planes"  Sacramento City College, Dec. 10, 2013.

"Functions, Duality, and Mapping Diagrams" Howard University Presentation, December 2, 2013, Washington, DC.
"Concepts to Drive Technology in the 21st Century" (html),  ComputerBasedMath ™(YouTube Video) (CBM) Education Summit, UNICEF, NYC, Nov.22 ,2013.
"Functions, Duality, and Mapping Diagrams" Forty-Second Annual State of Jefferson Mathematics Congress October 5, 2013, Orick, CA
"Logic is Not Epistemology:Should Philosophy Play a Larger Role in Learning about Proofs?" MathFest, Hartford, CT, August 2, 2013
"A Simple Proof of the Classification of Conics by the Discriminant ," MathFest, Hartford, CT, August 2, 2013
"Projection: Examples to Illuminate Unification, Generalization, and Abstraction."  HSU Colloquium, March 28, 2013
"Designing an Introduction to Proofs Course Understanding the Problem: Unification, Generalization or Abstraction?" JMM. San Diego, January 10, 2013 (pdf)
"The Benefits of A Habit: Examining Evidence to Understand Statements and Proofs." JMM. San Diego, January 12, 2013 (pdf)
"Learning from Newton" (pdf) HPM, Berkeley, CA 10-28-2012
Utah Workshop Materials:(1) Mapping Diagrams and (2) Sensible Calculus, July, 2012
"Square Roots: Adding Philosophical Contexts and Issues to Enhance Understanding." JMM, New Orleans, January 8, 2011 (pdf)
 "Two Different Approaches to Getting Students Involved in Writing Proofs ." JMM, New Orleans, January 07, 2011 (pdf)

Personal Stuff: A resume.(pdf) ; A biographical sketch.
HSU Pre-Law Advising Homepage  [I am one of the HSU Pre-Law Advisers]

POM SIGMAA (Philosophy of Mathematics) Find out more about this Special Interest Group of the MAA. 
HOM SIGMAA (History of Mathematics) Find out more about this Special Interest Group of the MAA.


This site is still under reorganization.
Links are being reconfigured and some are inactive or incorrect.
Older pages need reworking to be made handicapped accessible.
Links starting with "" are being readdressed as needed with ""
I continue to work on this.
Flash     :)