Liam bought 623 ounces of chocolate. 43.1 ounces of it was milk chocolate and the rest was dark chocolate. How much dark chocolate did Liam buy?

Liam bought 623 - 43.1 = <<623-43.1=579.9>>579.9 ounces of dark chocolate. Answer: \boxed{579.9}.

To find out how much dark chocolate Liam bought, we need to subtract the amount of milk chocolate (43.1 ounces) from the total amount of chocolate he bought (623 ounces).

Dark chocolate = Total chocolate - Milk chocolate

Dark chocolate = 623 ounces - 43.1 ounces

Dark chocolate = 579.9 ounces

Therefore, Liam bought 579.9 ounces of dark chocolate.

To find out how much dark chocolate Liam bought, we need to subtract the amount of milk chocolate from the total amount of chocolate he bought.

Given that Liam bought 623 ounces of chocolate and 43.1 ounces of it was milk chocolate, we can subtract 43.1 from 623 to find the amount of dark chocolate.

623 - 43.1 = 579.9

Therefore, Liam bought 579.9 ounces of dark chocolate.