Numbers, need help with a function

Look carefully:

Also, there shouldn't be a space between the "" so it can be used as 0 in other calculations.

=IF(ISBLANK($A2),"",10−$A2)

When people post formulas, just copy them, then in the cell type = and paste. You will avoid transcription errors.

Use:

IF(ISBLANK(A2)," ",10−A2)

(245448)

If your decimal separator is a comma (,) instead of a point (.) try replacing the commas (,) by semi-colons (;) in the formula.

What is the error message when you tap on the triangle at the end of the formula bar? Probably a syntax error.