How to Copy some number of files from one directory to another with cp command?

Question

I have 100 files in one folder. Their names are 1 to 100.

I want to copy files 1 to 50 into another folder named a. Something like this, which is not nice work:

cp 1 2 ... 50 ./a

Answer 1

cp `find . -maxdepth 1 -type f | sort | head -50` a

cp `find . -maxdepth 1 -type f | sort | tail -50` b