Statistical (aka Statisticality) - Partly a book, partly a set of demonstrations, and partly a tool, this app introduces you to basic statistics. Topics include box & whisker plots, histograms, median-median lines, linear regression lines, probability distributions, the Central Limit Theorem, and the normal curve. You can enter your own data or work with the provided sample data. Samples include information about US presidents, professional basketball players, coin flipping, dice rolling, the minimum wage, and the expansion of the universe! Each page includes a Read Me button for basic instructions and a Details button for information about the underlying mathematical concepts.

FactorMan - a game that tests your knowledge of factors. Play against the computer (FactorMan) or play against another person. Challenging fun for all ages.

Fractal Factory - Explore fractals and learn how they are created. Some depend on non-decimal arithmetic, some depend of mod arithmetic, and some depend on similarity transformations. See what's behind the scenes without getting bogged down in the programming details.

Calc Visualizer - Explore some basic calculus concepts. Eight modules help you visualize what differential and integral calculus are all about: Descartes' Method, Fermat's Method, Derivatives, Areas, Fundamental Theorem, Maximums/minimums, and Related Rates.

​LinePoints - Represent lines in a plane as single points. The line defined by y = 2x+3, for example, can be represented by the point (2,3). How can you find the intersection of two lines just by looking at their representations as points? Also represent hyperbolic and exponential functions as single points. The hyperbola defined by y = 4/(x-3), for example, can be represented by the point (3,4). Extensive documentation included.

Algernon - a program that challenges you to guide a mouse through a maze by giving it a series of forward, right, and left commands. You can give the commands individually or as a short series of steps.

All of the Mac software has been updated to run under the latest MacOS. The MacOS buttons link you to the Public folder of my personal dropbox, with the name of the zipped app at the top. Don't join or sign in. Just click on the download button (top right of screen) to download it to your computer. Then unzip it, and open it. Follow the same procedure for PC (Windows) software. The iPadOS buttons link directly to Apple's App Store.

Reckonings - a game which challenges you to reach nine target numbers by arithmetically combining a randomly selected group of four given numbers. ​Use addition, subtraction, multiplication, division, squaring, cubing, and parentheses in your equations.

​Recursivity - Partly a book, partly a set of demonstrations, and partly an exploratory tool, this app is all about recursive functions, chaos, and fractals. Investigate the Mandelbrot Set, Julia sets, Newton's method of finding complex roots, Sierpinski's triangle, Pascal's triangle, and patterns created by cellular automata. Explore mathematical beauty and complexity.

Arithmetic Quilts - a program that creates mod arithmetic tables using colors instead of numbers. Beautiful and intricate patterns result. Values in the tables are based on either basic arithmetic operations or on the results of recursive formulas.

Probability Simulator - Flip coins, roll dice, spin spinners, and investigate the probabilities of various outcomes. Also examine some challenging and seemingly paradoxical probability problems.

Mystery Motion - Try to determine the two-dimensional motion of an object as it travels across a table after observing only its one-dimensional motion as seen from the front or the side.

​Arithmetic Triads - arithmetic practice program emphasizing the relationships between adding, subtracting, multiplying, and dividing. Includes graphical representations of problems, and option to include negative numbers.

MathPats - Create spirolaterals, geometric patterns formed by a repeated sequence of segments and angles. Investigate prime numbers, search for special types of primes, and discover some surprising patterns. Start with any whole number between 0 and 99. If it is an odd number, then multiply it by 3 and add 1; but if it is an even number, divide it by 2. Repeat the process with the resulting number. Do this over and over. What happens in the long run? Does the sequence of numbers get pulled into a "black hole"? Change the rules - multiply by some other number and/or add some other number. Investigate the hidden beauty and complexity of the Mandelbrot Set. Zoom in on a specific region of the complex plane and vary the maximum number of iterations.

​Triangulator (aka The Triangle Center) - Explore the "centers" of a triangle: centroids, incenters, circumcenters and many more. Also learn about trilinear and barycentric coordinates.

ArithmeDarts - a game designed to build number sense and estimation skills. Aim the darts by specifying the coordinates of target balloons or predict whether at dart aimed at a certain coordinate will hit one of the target balloons. Lots of options are available in order to raise or lower the level of difficulty.