I have a checkbook spread sheet. I would like for the cells to display blank instead of $0.00
Use number format code [$$-409]#,##0.00;[RED]-[$$-409]#,##0.00;
(or similar, corresponding to your locale’s currency and display format, note the trailing semicolon that denotes an empty display string for 0) which is an equivalent of [>0][$$-409]#,##0.00;[<0][RED]-[$$-409]#,##0.00;""
and in fact after saving to .ods and reloading becomes such.