Numeration
- Abacuses: counting, Suan pan, Soroban, Roman, Stchioty
- The number circuit, a tool for developing the sense of operations and mental calculation
Solving basic problems
Basic additive and multiplicative problems. How to approach them with bar diagrams.
- Basic Additive Problems: Classifying Statements
- Modeling additive problems with the bar diagram
- The “plus-minus” machine: an alternative model
- The Multiplicative Bar Diagram
- The Cartesian Diagram – Another Model for Multiplication
Topology and reasoning
- The L game, the strategy of translations, symmetries and rotations
- Hanoi Mystery, the puzzle of upside-down towers with a hint of the unknown
- Flip-flop pinball: modeling a movement
- Sudoku: Organizing Space
- Admission to the Gorgias Academy: The Logic of True and False
Zebra puzzles
Games and techniques to solve all zebra puzzles. Progress at your own pace with our carefully measured puzzles, from the simplest to the most challenging. Use the zebra puzzle editor to solve them or even create your own.
- Zebra puzzles – summary
- Zebra puzzles: solving and designing
- Zebra puzzles: Universal techniques to solve them all!
- Zebra puzzles: Glossary of Programming Instructions
Turing Machine
The Turing machine is an alternative way of learning to code with a minimalist instruction set.
- The Turing Machine: Presentation