Dredge and Draw X effects?

[lordofthepit]

Suppose I have one dredger in the graveyard (say, Golgari Grave-Troll), and during my main phase, I play a Careful Study. I choose to replace one of the draws with a Dredge 6 from the Troll. Let's suppose it flips over another dredger (say, another Troll). Can I choose to replace the second draw off the Careful Study with dredge from the new card? Or do I have to announce both replacement effects before the dredge process begins?

My guess is that I can continue to dredge because my understanding that you draw cards separately, and each of them can be substituted with dredge as a replacement.

[heroicraptor]

You are correct.

423.2. Cards may only be drawn one at a time. If a player is instructed to draw multiple cards, that player performs that many individual card draws.