The puppies: 4 children × 4 backpacks × 4 dogs × 4 puppies × 4 legs × 4 toes =    4096
Plus the dogs:           4 children × 4 backpacks × 4 dogs × 4 legs × 4 toes =    1024
Plus the children:                              4 children × 2 legs × 5 toes =      40
Plus the driver of the school bus:                           2 legs × 5 toes =      10
                                                                                ------- +
This gives the following total number of toes:                                    5170