Why is it called a draw? There's no information as to why it's called a draw. Some of my students start to take out a pencil and paper and literally draw in the middle of the game.

Why is it called a draw?
I do not think that you will ever get a definitive answer. I did find an interesting article of a dedicated etymology site here.

I will quote part of it here:


  By the Oxford English Dictionary’s (OED) reckoning, the earliest
  record of draw, as in a contest that ends with no winner, comes in
  reference to an 1856 US chess match. Over the next few decades,
  writers marked off draw with quotes or italics, which shows the word
  was novel. The word was familiar by the 1870s. 
  
  This draw is short for draw-game, which the OED finds for a “tie” by
  1825. A draw-game, in turn, is a variation on a drawn battle or drawn match. The OED dates drawn match to a 1610 letter from English
  diplomat Sir Dudley Carleton: “It concluded, as it is many times in a
  cock pit, with a drawn match; for nothing was in the end put to the
  question.” (Before pilots occupied them, game-cocks fought in
  cockpits.)
  
  Why such a battle or match is characterized as “drawn” is unclear:
  Indeed, etymology often ends in draws. Drawn may be clipped from
  withdrawn, as in fighters who have withdrawn from the battlefield.
  Withdraw, “to take back or away,” features an old and original sense
  of the preposition with, “against,” even though it now, ironically
  enough, means “together.” Draw, meanwhile, is related to drag. And
  withdraw itself might be a calque, or loan translation, of Latin’s
  retrahere, “to retract.”


That is probably as close as you will get.