The sign for "zero" shows an "O" handshape and moves it forward with a firm stop.
ZERO:
The sign for "none" can be used for an emphatic "zero!"
NONE:
If for some reason you need to emphasize that the handshape you are doing is a "zero" and not an "O" (as in the alphabet letter coming after "n" and preceding the letter "P" then you can show the "zero" against your palm. If the context is clear, you don't need to use this method, but if you are talking about both letters and numbers (as in a password or some sort of product number that mixes letters and numbers) then using the palm is a good way to distinguish between letters and numbers. This version is also good for talking about grades. For example, if a student got a "zero" on an assigment.
ZERO (palm version)
Also see: ZILCH
Notes: