Back in time to 100 BC, what knowledge would you impart to the people?
GavinB: You almost certainly know whatever level of mathematics is above the one available. In the Mediterranean at this point in history, they're just circling around the idea of integration, but won't actually make it there.Here's a protip: download wikipedia to your phone today. As soon as you realize that you've been trapped in the past, turn it off. Turning it on briefly will allow you to access stores of vital information before the battery runs out.Unless this is Terminator rules, and you're naked . . .