@gungasnake,
Washington was articled as a surveyor at age 15. He didn't make anything like that kind of money. There was little suveying to do in the settled part of Virginia, so he only made money on commissions, which were, to say the least, unreliable. Where he made his pile was in surveying parts of Virginia which had
not been settled, when he was entitled to make claims of his own, and, of course, he had actually seen the land. He didn't make money off of that until after the revolution, and even then, more than half his land was simply stolen by squatters. He never enforced those claims, though, believing that most of the squatters were veterans of the revolution.
As for truancy, with no public school system, it wasn't an issue. Just about everyone who had to make a living in life was about their business by 14 at the latest--many apprentices started at 11 or 12. This is apples to oranges stuff--that era is not comparable to our contemporary world at all.