Some of these overlap with what others have suggested. 0a) Build a simple video game. 0b) Implement a simple encryption scheme (eg. ROT) to exchange messages.

Some of these overlap with what others have suggested. 0a) Build a simple video game. 0b) Implement a simple encryption scheme (eg. ROT) to exchange messages. 1) History of computing. Not just the superficial but how it was, how we got here. Turing's ACE & Neumanns EDVAC report. 2) Interest rate computation. Modeling loans. 3) Forth programming language. 4) Data privacy. How user data is tracked, manipulated and financialized. 5) How computing systems are insecure and not to trust them blindly.