Its really simple all you have to do is put the number and what learned from Avatar The Last Airbender. the goal is to get to 500.
1. The Avatar was in suspended animation for 100 years
2. Aang is the last airbender
3. The Last Avatar before Aang was a Firebender Named Roku.
4. Avatar Roku was best friends with Firelord Sozin back when he was Prince Sozin and they share a birthday.
5. Aang is the youngest Avatar to learn he is the Avatar.