How do I change a simple subtraction function =B3-A3 to return a blank cell if either of the 2 cells is blank?
Short answer
=IF(OR(ISBLANK(B3),ISBLANK(A3)),"A3 or B3 are blank",B3-A3)
Explanation
- Use ISBLANK to test if cell is blank
- Use OR to check if any of its arguments is true
- Use IF to return something if the condition returns true and other thing if the condition returns false