**"The History of Logarithms:A glimpse of some highlights." Occidental College Colloquium, LA, CA. November 23, 2010**

**"The Articulation of Mathematics-A Pragmatic/Constructive Approach to The Philosophy of Mathematics." JMM, San Francisco, Jan.14, 2010.***"Which Came First? The Philosophy, the History, or the Mathematics?"*Mathfest 2009, Portland Oregon, August 6, 2009**Visualizing Linear Functions with and without Graphs!**(Power Point Presentation)**Saturday October 25, 2008 CMCFN Conference, Arcata, CA**MAA Minicourse #13*Teaching and the philosophy of mathematics.***January 6 and 8, 2008****. San Diego, CA.****"What Place Does Philosophy Have in Teaching Mathematics?" Preliminary report.**(.ppt file)**MAA Jan. 6, 2007**- "Real Numbers: Models and The Proof of The
Continuum Hypothesis " (.ppt file) Math Dept.
Colloquium, CSU Sacramento, November 9, 2006.

- "Math and Music" (.ppt file) Presentation at MESA,Cabrillo College, Sept. 14, 2006.
- "Life on a Torus:Some of the Mathematics from the World of Pacman", CSUMB Colloquium, Sept. 15, 2006
- "Mathematics, Music, and the Guitar" (.ppt file).", Occidental College Colloquium, April 21, 2006.
- "Dynamic Visualization of Calculus I-III " CSU Dominguez Hills Mathematics Colloquium, March 1, 2006
- "
*Visualizing Partial Derivatives without Graphs.*" MAA Jan. 14, 2006 (pdf) - "
*The Square Root of 2, Pi, and the King of France: Ontological and Epistemological Issues Encountered(and Ignored) in Introductory Mathematics Courses.*." MAA Jan. 12, 2006 (Power point) - "The Incredible Number 7 " Occidental College Colloquium (Power Point Presentation) Sept. 16, 2005
**"Winplot -Freeware for Pre-calculus through Calculus III and Differential Equations**" CMC^{3}Dec. 3, 2004- "
**Estimating Integrals Using Polynomials:****A Tale of Two Problems (and a little history as well)**

Eureka High School, May 27,2004 - Winplot 2 Hour Workshop at AMATYC Conference, Salt Lake City, Nov. 15, 2003
- "Winplot -Freeware for Pre-calculus through Calculus III and Differential Equations" ICTCM Nov. 2, 2002
- "Using Probability to Understand Calculus ", MAA Jan. 7, 2002
- "The Continuum Hypothesis: A Look at the History of the Real Numbers in The Second Millennium. ", MAA Jan. 7, 2002
*"Some Early History of Logarithms"*, Dept. of Mathematical Sciences Colloquium, New Mexico State University, March 20, 2001.ICTCM 12 Nov. 6, 1999*Technology and the History of Mathematics***Dynamic Visualization of PreCalculus and Calculus Concepts with Geometer's Sketchpad (AMATYC Workshop).**Nov. 5, 1998- "Dynamic Visualization of Calculus I-III with The Geometers' Sketchpad" Mathfest '98.
**"Concepts to****D****rive****T****echnology****"**, in*Proceedings of the Fifth Annual International Conference on Technology in Collegiate Mathematics**,*edited by Lewis Lum, November,1992.

- UMAP Editorial
**(1990) 11 : 93-96.***A Sensible Calculus.* - "Differential
Equations:
A
Motivating
Theme
for
Sensible Calculus." An unpublished paper related to one
theme of the Sensible Calculus. I welcome your comments on it.

- HSU Math Dept. Colloquia:

- "The Articulation of Mathematics: An Everyperson Pragmatic/Constructive Approach to The Philosophy of Mathematics" April 8, 2010
**"**(.ppt file), September 3, 2009*Visualizing Linearity: Alternatives to Line Graphs*",(.ppt file) Sept. 2, 2004**"Models, Numbers, and Measure Theory:**The Independence of The Continuum Hypothesis. In memory of my mentor, Jean van Heijenoort"*"***The Door Swings Both Ways:***: Making Calculus Sensible with Economics or Economics Sensible with Calculus"*, December 11, 2003- "
*Mathematics Beyond Good and Evil: Duality in Geometry, Algebra, and Calculus!"*Thursday, November 21, 2002 -
*"What Is Topology and Why Is It Useful?"*Thursday, March 7, 2002 -
*" The Possible and the Impossible: Some examples of the use of models and their consequences"*Dec. 6, 2001 -
*"The Continuum Hypothesis: A Look at the 20th Century History of the Real Numbers from Cantor to Cohen/Scott/Solovay"*Sept. 14, 2000 -
*"Life on a Torus: Some of the Mathematics from the World of Pacman"*Sept. 30, 1999 -
*"The History of Logarithms: A glimpse of some highlights."*Feb. 4, 1999. - "
*Mathematical Encounters with the Number 7*." Sept. 10, 1998. - "
*Solving Calculus Problems without Calculus.*" April 2, 1998 - "
*Dynamic Visualization of Calculus.*" September 18, 1997

- JavaSketches (not working)