computer aithmetic is accomplished using what number system?

Question

-octal,hexadecimal,decimal or binary.
plz help
if you can give an example please.

Answer 1

The answer is binary.
Sorry but this is the best example I could find.
There is a lot more to this than just binary. Most of us look at computer data in hexadecimal simply because it is more compact than binary.
But a computer will use different data types to represent different things and show this data in different ways.
ie. Characters and binary coded decimal for example

Answer 2

hex