Subtraction Function

What is a simple subtraction formula from one cell to the next?

You mean =A1-A2?

A spreadsheet function is not needed, only the operator -. For example, enter 5 in A1 and =A1-3 in B1.

result in B1

Similarly, +, * or / can be used for addition, multiplication or division respectively.

Apart from the minus operator, you could also use the built-in Calc function RAWSUBTRACT()

Calc function RAWSUBTRACT