B1: = A1
B2: = A2-B1

copy B2 down

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)

"Coopster8" wrote in message
...
need a formula to add and subtract and give me total..trying to show
inventory level dropping or raising on a weekly bases...something like
this
week 2- week 1, week 3 - week 2, week 4 - week 3, week 5 - week 4 = total,
or
week 1 = 12
week 2 = 15....3
week 3 = 4....(1)
week 4 = 18...17
week 5 = 5....22
total = 22