Will lets say box one is red (r), box two is green(g), Box three is blue(b) and box four is yellow(y). If you have 10 tennis balls then 2 tennis balls in the Red Box, 2 tennis balls in the green box, 2 tennis balls in the blue box and 2 tennis balls in the yellow box now you should have two left over so but one in the Red box and the other in the Blue box! I don't know if this is right but I am a little confused on what your saying so Hope this helps:)
