One example of how the book and the movie are different is, in the book the indians were placed in each room and they disappeared after each death happened. In the movie the indians were all in the kitchen and after each death one got broken. I think they changed this in the movie because it was easier to have them all together instead of in each room so when they counted them they didn’t have to go room to room.
Another example is in the first part of the movie it started out in a boat. In the book they start out in carriages. I think they changed it in the movie because it would have been easier for them to have already gotten their letters and on their way to the island on the boat than them receiving the letters