limiting data input

[Fleming]

I have three different items to calculate for a ranking system. I wan
to make sure that when someone uses the checklists that if there is
figure in one of the cells then figures cannot be inserted into th
other cells. The cells are in a column under each other and ar
multiplied by a ranking number in the cell alongside each one of them.

Item Ranking Answer
A 6
B 6
C

 

[Frank Kabel]

Hi
have a look at 'Data - Validation' and use a custom formula such as:
=A1=""
to allow only entries if A1 is blank