My wife is a hotel breakfast hostess. Her boss wants her to keep a weekly
inventory of breakfast food items. In trying to EXCEL it I run into a
problem.
Three columns: Previous Inventory, Additions/Subtractions(+/-), New Inventory.

If I add +/- to Previous Inventory to get New Inventory I get a circular
reference problem.
To avoid this I figure she will have to input Previous Inventory (manually)
from New Inventory and then input +/- to get a 'new' New Inventory. Is there
a way to avoid the double manual input and avoid the circular reference
problem?