What is the unnecessary 0 at the end of a decimal known as? (Example: 4.50)?

Question

I know that the optional comma before the "and" in a list is known as the Oxford comma (example: We bought apples, bananas, and oranges...). Is there a similiar name for the optional 0 at the end of the decimal?

Answer 1

In scientific notation we refer to this as a "singificant figure."

Answer 2

a space holder

Answer 3

I call it a "trailing zero".