Practice makes permanent

Interactive Exercises

Reading about computational thinking is one thing. Doing it is another. These 12 exercises put the concepts from the book into your hands — no screen skills required, just thinking.

Finger Binary Counter
beginner Binary Numbers

Finger Binary Counter

Count to 31 on one hand using the binary number system. Discover how computers represent numbers.

Caesar Cipher Machine
beginner Encryption

Caesar Cipher Machine

Encode and decode secret messages using the same cipher Julius Caesar used to communicate with his generals.

Fact or Fiction Quiz
beginner Boolean Logic

Fact or Fiction Quiz

True or false? Test your logical reasoning by evaluating statements that computers deal with every day.

Pattern Spotter
beginner Pattern Recognition

Pattern Spotter

Spot the pattern, predict the next item. One of the most powerful skills a coder — or anyone — can have.

Bug Hunt
beginner Debugging

Bug Hunt

Something has gone wrong in these code snippets. Can you find the bugs and fix them?

River Crossing Puzzle
intermediate Algorithms

River Crossing Puzzle

Get the fox, chicken, and grain across the river without any disasters. A classic algorithm puzzle.

Loop Machine
intermediate Loops & Iteration

Loop Machine

Build musical loops by repeating instructions. See exactly how computers execute the same steps over and over.

Sorting Playground
intermediate Sorting Algorithms

Sorting Playground

Race different sorting algorithms to find the fastest way to put things in order. Bubble, selection, or insertion?

Variable Suitcases
intermediate Variables & Types

Variable Suitcases

Pack different types of data into labelled suitcases. Learn why computers care about what kind of thing is stored.

Boolean Logic Cards
intermediate Boolean Logic

Boolean Logic Cards

AND, OR, NOT — the three logic gates that power every computer. Combine them to solve logic puzzles.

Decomposition Tree
advanced Decomposition

Decomposition Tree

Break a big problem into smaller and smaller pieces until each one is easy to solve. The coder's superpower.

Flowchart Builder
advanced Algorithms

Flowchart Builder

Design step-by-step solutions using decision diamonds and process boxes — the language of algorithms.