I think the Fibonacci number page isn't a great example since it explains the middle school version in the first few lines. It only goes into depth much later.

I think the Fibonacci number page isn't a great example since it explains the middle school version in the first few lines. It only goes into depth much later. The Excess 3 page however has a really complicated first paragraph where only about 5 words even attempts to explain what it is (a self-complementary BCD) and then again uses 2 terms that you might not know. BCD has a useful link to another article but what does self-complementary mean? I only see a mention of ones complement all the way down in the motivation. It also fails to explain how addition/subtraction work so you have to figure that out yourself. After a good amount of reading I could understand it and why it's actually cool but by god it wasn't as easy as it could have been.