Raj Raizada headshot I am a math and computer science educator based in NYC. I work as an interaction developer at Desmos, creating online tools for teaching math. Some examples of Desmos activities that I made before joining the company can be found here.

I also have some limited availability to do tutoring: math and/or coding, online or potentially in person. It brings me joy when kids experience an "Aha!" moment. A couple of quotes from former students of mine:
"Thank you for being the first person to show me I can do math".
"I feel like my 3rd eye has opened. It makes so much more sense!".
For queries, please send me an e.mail.

For two years I taught high school and middle school math, and greatly enjoyed it. Before switching to school teaching, I was a cognitive neuroscience faculty member in a university, teaching and carrying out brain imaging research (publications here).

I especially enjoy creating interactive math demonstrations and games. Below are some examples, in Python, Desmos, and javascript.

What makes code or an activity useful for teaching?

In my experience, students tend to find an activity or a piece of code engaging if it is:

Some simple tutorial Python code

PyTurtle examples to illustrate math concepts, running in the browser via trinket.io.

Python string art
Python string art
Python billiards GCF
Math billiards GCF
Right triangle fractal
Fractals and recursion

Tutorial python code running in the browser via Google Colab.

Linear classifier
Linear classifier
Divisors math game
Simple math game: divisors
Neural network XOR
Neural network

Desmos activities

Desmos is a really wonderful tool for making interactive math. It's a graphing calculator, but you can do much more with it, including making activities and games. Below are some examples that I've made. More of my Desmos creations can be found here.

Snakes game: trig graphs
Python billiards GCF
Radian angles: space invaders
Right triangle fractal
The 17 wallpaper groups

Below are a couple of embedded Desmos graphs that I made. The first is a snowflake maker. It can be used for teaching about mirror and rotational symmetry, but beyond that it's simply fun to play with. Drag around the fuzzy white dot to draw patterns. Hit the "RESET" button in the lower right to clear the screen.




Here's an animation showing a proof of the Pythagorean Theorem by area-preserving shearing. I added an animated gif of it to the Wikipedia page for that theorem, here. (Other contributions I've made to Wikipedia are collected here.)



Javascript math games

I've recently started exploring making math games in javascript, so that they can run directly in any web browser. I've been using the libraries p5.js and p5play.

The task in the two examples here is to match math blocks whose numerical values are equal. Those values can be expressed in terms that span a broad range of the math curriculum, from simple addition all the way up to calculus.

Math "candy crush": match block values
Math-matching platformer game
Simulation: Galton board statistics










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