Delete digits in iPhone OS 3.0 Calculator

For all those missing the backspace key in the Calculator (to remove a number you just tapped), just think like Apple: a little swipe over the display will do it.

Seems quite consistent to me, as you also do this to delete stuff in other parts of the UI, like lists. I don’t really understand why this isn’t mentioned in the User’s Guide — are they betting on when someone finds out?

[robg adds: I don't know if this worked in iPhone OS 2.x]