Department of Mathematics
Cal Poly Humboldt, formerly Humboldt State University
Arcata, CA 95521

EMAIL:flashman at
Cell Phone: 707-832-9973
Illustrating Desargues' Theorem with a            3-D Model.

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

Fall, 2017 - Spring, 2020, Fall, 2021- Spring, 2024:Visitor to University of Arizona Mathematics Department, Tucson, AZ.

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 8-2017)
Papers/Presentations/etc. [2019-2024]

Mathematics Educator Appreciation Day (MEAD). Tucson, AZ. " 'And Then'... Compositions of functions-They're Everywhere ". January 27,2024
Joint Mathematics Meetings, San Francisco, CA.
    AMS Special Session on Mathematics and Philosophy."
Do We Need a Separate Philosophy of Geometry?" Jan. 5, 2024.
Fall 2023 ArizMATYC Conference, Chandler AZ. "Visualizing the algebra of equations and inequalities with mapping diagrams." October 6, 2023
Mathematics Educator Appreciation Day (MEAD
(Links) "How Many Ways Can You Solve a Quadratic Equation Visually?" Tucson, AZ. January 21,2023    .

48th AMATYC Annual Conference Virtual Days. "Darts-Visualizing Probability: Simulations, Graphs & Mapping Diagrams" . (GeoGebra book with video) Dec 2, 2022.
BEAM Summer Away, LaVerne University, LaVerne, CA, two one week courses, July 5-19, 2022.
Mathematics Instruction Colloquium, University of Arizona. "GeoGebra: Why I Use It. Should You?".(GeoGebra Book) April 4, 2022.
ArizMATYC/MAA Southwestern Section Joint Conference, "Visualizing Linear and Nonlinear Functions and Transformations of Several Variables with Mapping Diagrams"

    ASU Polytechnic Campus, April 1, 2022 (GeoGebra Book:
Mathematics Educator Appreciation Day (MEAD
Visualizing Calculus With Mapping Diagrams: Making Sense Of Differentiation And Integration.Tucson, AZ. January 22,2022.
CMC-South Annual Conference 2021, "
Visualizing the Algebra of Equations with Mapping Diagrams". November 6, 2021. (Links)
14th International Congress on Mathematical Education,
"MAPPING DIAGRAMS: FUNCTION VISUALIZATION OF REAL AND COMPLEX ANALYSIS AND MATRIX ALGEBRA", Shanghai, July 14, 2021. Topic Study Group 23 Visualization in the teaching and learning of mathematics (GeoGebra Book includes Paper) (On YouTube)
ATM Conference 2021. "Visualizing the algebra of equations and inequalities with mapping diagrams", April 7 & 8,2021. (Links)
AMATYC Webinar
, "Visualizing Solving Equations with Function Mapping Diagrams September 22, 2020. (On YouTube.)
Joint Mathematics Meetings
Denver, CO Jan. 15&17, 2020: MAA Minicourse 2020:
Visual Complex Analysis- GeoGebra Tools and Mapping Diagrams GeoGebra Book.
HSU Math Department Colloquium,
"Linear Algebra & Mapping Diagrams: Old & New Visualizations"
(GeoGebra Book)  Sept. 5, 2019.
Proceedings of Bridges 2019: Mathematics, Art, Music, Architecture, Education, Culture, Edited by Goldstine, McKenna, and Fenyvesi, July, 2019, pp 295-302.

    "Mapping Diagrams and a New Visualization of Complex Functions with GeoGebra"
    Mapping Diagrams and Visualization of Complex Function. GeoGebra book,, July, 2019.
MEI Conference 2019 (Bath, UK), Saturday, June 29, 2019.
    "Visualizing Functions with Mapping Diagrams"
    "Visualizing Calculus with Mapping Diagrams"
ICTCM 2019 (Scottsdale, AZ). Saturday, March 16, 2019.
    "GeoGebra Tools for Visualizing Integration with Mapping Diagrams"
    "GeoGebra Tools for Creating Mapping Diagrams: From Worksheets to Books"

Recent (back to 2011) Stuff.

Not So Recent (before 2011) Stuff.

My Bookmarks (old)
A resume.(pdf) ; A biographical sketch.

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.


WORK IN PROGRESS (1-14-2023)

This site is still under reorganization. It is now moved from a server at Humboldt State University to one at
Links are being reconfigured and some are inactive or incorrect.
Older pages need reworking to be made handicapped accessible.
Links starting with "users," are being readdressed as needed with ""
I continue to work on this.
Flash     :)