‘What’s this?’ the boss asks.

‘Ave you gotta no brain?  Tree and tree and tree makes a nine,’ says the
Italian.

‘Fair enough,’ says the boss.  ‘Here’s your second question.  Use the
same rules, but this time the number is 99.’

The Italian stares into space for a while, then picks up the picture that he
has just drawn and makes a smudge on each tree. ‘Ere you go.’

The boss scratches his head and says, ‘How on earth do you get that to
represent 99?’

‘Eacha of da trees is a dirty now.  So, it’s dirty tree, and dirty tree,
and dirty tree.  Datsa a 99.’

The boss is getting worried that he’s going to actually have to hire this
Italian, so he says, ‘All right, last question.  Same rules again, but
represent the number 100.’

The Italian stares into space some more, then he picks up the picture again and
makes a little mark at the base of each tree and says, ‘Ere you go.  One
hundred.’

The boss looks at the attempt.  ‘You must be nuts if you think that
represents a hundred!’

The Italian leans forward and points to the marks at the base of each tree and
says, ‘A little doga come along and shita by eacha tree.  So now you gotta
dirty tree and a turd, dirty tree and a turd, and dirty tree and a turd. 
Data makea one hundred.  So, whenna I start?