> What is #///? My image does not know it.

Ah, this is one reason why I insist my changes are to be reviewed :)

#/// is a method I came up with and that I use very often, it is simply 
syntactic sugar for float conversion before division, to avoid 
introducing Fractions in computation (this can slow things down 
considerably)

In Number, it is simply

/// aNumber
  ^ self / aNumber asFloat

So you can get rid of it by adding a #asFloat and replacing it with #\

Stef