Simple. I assume the ones going to the middle school are currently in 5th grade at the elementary school. You have 126 coming into the middle school from each school. You need to multiply 126 by 4. You get 504. There will be 504 new students at the middle school.
Answer: any of two or more actual representations of a morpheme
The following sentence contains an adverb clause.
This sentence contains two clauses - an independent clause (We moved) and a dependent/subordinate clause (because our house was too small). Given that the second sentence gives us a reason why they moved, it acts as an adverb, which is why it is an adverbial clause.
