Little Johnny was being questioned by the teacher during an arithmetic lesson. ‘If you had ten dollars,’ said the teacher, ‘and I asked you for a loan of eight dollars, how much would you have left?’

‘Ten,’ said Little Johnny firmly.

‘Ten?’ the teacher said ‘How do you make it ten?’

‘Well,’ replied Little Johnny ‘You may ask for a loan of eight dollars, but that doesn’t mean you’ll get it!’