If you buy the Artifact Detector you can find them easier.
By getting 2 Finished Artifacts in TLC & finishing Ancient city
If you get all the artifacts from one level, then you can go to a room where you have a bunch of minikit models, and you can scroll through them and see wich ones you've completed. That's how it is for DS
The math class in LEGO Indiana Jones is some where in a level at least that's what my cousin said. And the right level is in the last crusade and the level is rescue professor Jones :)
beat the first level.
By playing the first level of Temple of Doom you unlock him for free play.
complete the first level
Run and Jump
You must complete everything else in the game to get that level.
Play the Raiders Of The Lost Ark: The Lost Temple level. Find the room that is sealed off by metal Lego pieces. Use a bazooka or grenade in Free Play mode to reach him.