Does scry count as card draw for abilities that trigger when you draw a card?

Scry and drawing are two completely separate game actions with different rules definitions. Drawing a card is defined in CR 120.1 as taking the top card of your library and putting it into your hand. Scry, defined in CR 701.18, lets you look at the top N cards of your library and put any number on the bottom and the rest back on top — no card ever enters your hand during this process.

Because scry does not move any card into your hand, it does not satisfy the condition of 'drawing a card.' Any triggered ability that says 'whenever you draw a card' (such as the one on Jace's Erasure or Pursuit of Knowledge) will not trigger when you scry, regardless of how many cards you look at.

It is also worth noting that even if scry causes you to put a card on top and then you subsequently draw it, only the actual draw step triggers those abilities — not the scry that positioned the card there.

Concrete example: You control Jace's Erasure, which says 'Whenever you draw a card, target player mills a card.' You cast Preordain, which has you scry 2 and then draw a card. The scry 2 does not trigger Jace's Erasure at all. Only the single draw at the end of Preordain's effect triggers the ability, causing one card to be milled.

References: CR 120.1 (drawing cards), CR 701.18 (scry keyword definition).