I am not just trying to teach him programming but also show that with a bit of organization and working little bit each day you can achieve pretty huge results. So we created a very simple version of a game. I have then created a document where we are maintaining a listing of functionality we want to add. We then take them one by one, discuss how it can be added to the game and then tick off once it is done.

A Texas Instruments programmable calculator. He read the manual, played with it a bit, then found out he could automate some of his homework. Then found out he could make simple games. Then fairly impressive games.

After that, he did a bunch of Minecraft programming and loved it.

Fast forward a decade and he smokes through Advent of Code without breaking a sweat, and is a co-founder and CTO.