Different staff sizes in the same file.

Hello,

I am writing small exercises and melodies for my beginner students.
At the beginning I want the notes to be big so it will be easier to read, but later on the students get better in reading, and the piece become longer, so I want the size to be smaller.
I made the size big using the "Scaling" field in the "Page settings" dialog.
But it seems to me that this setting is same throughout the whole file, regardless of page breaks.

Is there a way to achieve this without separating to several files?