How to avoid a 0 when linking to a blank cell with formatting

Here's the situation, i want cell B1 to be linked to cell A1, so that when i enter data in to cell A1 it appears in B1 as well. However, when A1 is blank, i do not want B1 to show a zero. I know the problem can be solved with the if() function, but I believe there must be a formatting option to solve this. is there one? I've attached a file for more information.