Assumptions:

1) Workbook1.xls Sheet1 contains your pricing, and that Column A
contains the book name and Column B contains the price.

2) Workbook2.xls Sheet1 contains your orders, and that Column A contains
the book and Column B the quantity.

Formula:

[Workbook2.xls]Sheet1!C1, copied down:

=B1*SUMPRODUCT(--('[Workbook1.xls]Sheet1'!$A$1:$A$100=A1),--('[Workbook1.
xls]Sheet1'!$B$1:$B$100))

Hope this helps!

In article ,
"Watercolor artist" <Watercolor
wrote:

I have a column in one spreadsheet (Call it "Orders") into which I enter a
book name that I sell, a second column into which I enter a quantity, and a
third column into which the price is entered by looking up the book and
quantity in a different spreadsheet (call it "Pricing") in a different file,
finding the book's price, multiplying the quantity by the price, and
inserting that into the cell containing the lookup function. I don't know how
to write that formula and would appreciate help.