When I was 9 or 10 years old, here's how I made money:

lawn mowing
leaf raking
chicken house cleaning
greeting card selling
garden seed selling
snow shoveling
service station lot sweeping
car washing
pop-bottle returning (this was before the days of recycling)
pitching and catching and general tot corraling for the phys ed
teacher who ran the town's little league

And, last but not least, buying cigarettes from Jerry's By-Lo
grocery and delivering them to the guys in town who were too
lazy to go after their own. Yes, I did this and they sold them
to me without a hassle in those days. Everybody knew I did
this, I needed the money, and there were no questions asked.