Wrapping your head around abnormal mathematical concepts like negative numbers can be tricky. But thanks to maker and developer Russell Eveleigh, understanding these somewhat strange numbers is easier than ever thanks to his Zero Pairs project. This Raspberry Pi-powered creation serves as a visual aid to help understand negative numbers using a concept known as zero pairs.
The idea behind zero pairs is to provide a mental apparatus for the seemingly contradictory way negative numbers behave in equations by introducing positive and negative values that cancel each other out. Eveleigh's Zero Pairs project of the same name, is essentially a custom display panel that rotates balls around to represent numerical values. It's paired with a web-based user interface that you can use to enter equations and adjust various settings.
The top row consists of eight spheres that are black on one side and white on the other. Servos rotate the spheres to show the white color when representing a positive value. The bottom row has eight spheres that are black and orange to represent negative numbers. When you enter the equation on the web app, the display will provide a visual representation of the positive and numbers, making it easier to see how negatives behave.
The main board behind the project is a Raspberry Pi Zero (not the newer Raspberry Pi Zero 2 W) but you could get away with using a bigger Pi model like a Raspberry Pi 5 if you wanted to but it isn't necessary. The Pi Zero is connected to an Adafruit Servo Hat which operates the spheres on the display. The spheres were 3D printed and designed just for this project to mount directly to the servos.
The web interface is handled using Flask and operates from the Pi Zero as a basic HTML page. Eveleigh was kind enough to make the project open source which is fantastic as it's designed to be a teaching aid so you can peruse the source code in its entirety over at GitHub.
If you want to get a closer look at this Raspberry Pi project, you can see it in action over at Eveleigh's official YouTube page. You can also read more about the project's construction over at Eveleigh's Medium page.
