Take a look at =Vlookup()

You can do something like this in column D:

=IF(ISERROR(VLOOKUP(A1,[book2.xls]Sheet1!A$1:C$999,3,FALSE)),0,
VLOOKUP(A1,[book2.xls]Sheet1!A$1:C$999,3,FALSE))

where book2.xls, sheet1, A1:c999 contained yesterday's numbers.

Then use column E to do your subtraction.


Rich wrote:

I am using Excel 97.

I need to compare two different worksheets. The worksheets represent
daily sales activity. Column A in both worksheets represents the
customer ID, Column B is product description and Column C is sales
amount.

If the Customer ID (Column A) in yesterday's data appears again in
today's worksheet, I am to compare the sales (Column C ). I am to
substract yesterday's sales from today sales. The new report is to
appear in another worksheet like the example below.

Customer ID Item Description Sales

1 Bonds $1,000,000
2 Stocks ($100,000)

Any ideas how to approach this problem.

--

Dave Peterson