The VAT exercises have been likened to the decimilisation changeover. This is dangerously misleading. With decimalisation one could secure a taste of the new world by playing games with decimal currency (often in plastic form). This is not possible with VAT. There was a limited amount of knowledge to glue in the minds of decimal trainees — in the case of VAT we are by no means aware of all the complexities it will create. A lot of decimal training was mechanical: VAT training demands more thinking and reasoning, the quantity of knowledge to be absorbed is quite substantial. It is only when that knowledge is absorbed that we can begin to perceive the answers to problems posed by VAT.