(It`s very difficult to compute how much an item costs in dollars

[zoobinshid]

Hello everyone,
Would you please tell me why this sentence is wrong?
(It`s very difficult to compute how much does an item cost in dollars )
This is the right one I think but I don`t know why?
(It`s very difficult to compute how much an item costs in dollars )

Thanks for your help,

[Tdol]

It's an embedded question- the first uses a question word order, but you are not asking a question, but describing the situation- you don't want the listener to tell you the answer.

PS, I'd prefer 'calculate' instead of 'compute'.