I am trying to hide a value of 351 in a cell until the 351 is used in a
calculation. How do I do this. Example:

b3 is 351 I would like to subtract b2 which is 345 and show the sum of 6 in
b3. Until I fill b2 with a value, b3 is showing 351. I want to hide the 351
until the value is calculated.