First let's discuss what matched…
August had a deformed face like it was in the book. It also had almost all the lines in the book. It had maranda,via,justin and all the characters in the book it had starwars stuff in his room, He got and was wearing an astronaut helmet from miranda and all that stuff...
Now… let's consider the areas where the movie didn't follow the book… in the book it said the movie was the sound of music… but in the movie the movie was wizard of oz. In the book it said nothing about new year's eve. And when auggie pullman was in the woods with jack it was daytime… in the book it was dark… and the book told us nothing about jack bleeding on the back of his head.
Overall