Originally Posted by joeu2004[_2_]

"JonathanK1" wrote:
So, I have a worksheet with products down one axis and
dates across the other (dates up top). The data in the
middle is the number of products for each given day.
What I want to do in the next tab/worksheet is pick the
product and the date range, and have the added number show
up. For instance, Product A from April 1st to April 25nd
equals 25 (because I chose product A and because there
were 1 of them each day).
[....]
So here is what I have so far...
=SUM(INDEX(TOTALS!B2:NC90,0,MATCH(I7,TOTALS!B1:NC1 ,0)),
(INDEX(TOTALS!B2:NC90,0,MATCH(I9,TOTALS!B1:NC1,0)) ,
(INDEX(TOTALS!B1:NC1,0,MATCH(I11,TOTALS!A2:A90,0)) )))
[....]
The first index in the formula above is the FROM and the
next is the TO - the last is the product choice.

=SUMPRODUCT((TOTALS!A2:A90=I11)*(I7<=TOTALS!B1:NC1 )*(TOTALS!B1:NC1<=I9),TOTALS!B2:NC90)

You might want to use addresses of the form TOTALS!$A$2:$A$90, but leaving
I11, I7 and I9 as is if you want to be able to copy the formula across
several columns. For example, if J7, J9 and J11 represent another
date/product combination; K7, K9 and K11 represent a third; etc.