Arrange $$28$$ balls to form a square.  One ball is placed at each corner of the square.  How many balls are there on each side of the square?~\uline{~~~~~~~~~~}~ 
Overseas Competition->Knowledge Point->Word Problem Modules->Questions Involving Squares->Hallow Squares
Put $$1$$ ball in each corner ($$4$$ balls in total).  Remaining balls: $$28-4=24$$  $$24\div4=6$$  So, each side has $$1$$ ball at each corner and $$6$$ balls in the middle, giving a total of $$8$$ balls. 