Move 8 cubes depening on what round

Hi everyone ! i have 8 cubes thats around a smaller cube in the center. What im trying to do is to make a cube mov towards the center so that the smaller cube can dodge it and i want to send more cubes flying depending on what round it is, ex round 2 send 2 random cubes from the circel, round 5 send 5 cubes from the circel. Any takers ? im still new to unity XD thanks in advance