Help with remembering a maths trick please?

Question

A while back, someone ran through a maths trick with me but I've forgotten how it goes. I was told that a child had around 33p and was buying one-penny sweets. We counted down the pennies as they were spent, and the sweets were distributed to her friends, right down until there was no money left. Then when we reversed the process, we added the sweets/money up and the result was that there was one extra than there should have been.

I cannot remember the exact trick (and I'm sorry my description is so sparse on detail) but I've been trying to remember it again so that I can look into how it was done. Can anyone help me with this trick please, as I've lost contact with the person who told it to me?

Answer 1

I expect it relied on the inexact use of English .... perhaps by 'counting' zero one way and not the other ?