The Classroom

Tools, simulators and games

Learn by doing. Everything runs in your browser. Free tools are open to everyone; premium tools open with any unlocked level.

Number System Converter

Binary, denary, hexadecimal and octal with the working shown, plus two's complement.

Image, sound and text file sizes from the numbers in the question, with every step and unit.

Every level has its own guided projects, matched to the stage. Pick your level to start.

Step-by-step lessons to use with the runner, written for each level.