Sum formula

[helpmeplease123]

Ive created a basic sum formula, lets say its just like SUM((A1*A2)+(B1*B2)). Normally when its more like SUM(A1:C1), I can take the final cell, drag it down and itll do SUM(A2:C2) automatically. but when i draft this new one down, it changes it to SUM(A2*A3)+(B2*B3) and i want it to be drag it down and get SUM((A1*A3)+(B1*B3)) and then a1 a4 and b1 b4, etc

[shg]

Welcome to the forum.

You don't need the SUM function:

=A$1*A2+B$1*B2

See Help for About cell and range references

[helpmeplease123]

thanks a lot that worked!

[helpmeplease123]

Oh, Also:

When Ive got a document with 3 different spreadsheets on it (3 different tabs on the bottom) is there a way that with a 4th tab/spreadsheet I can use a formula to add up cells from different tabs? I mean like cell A1 from each spreadsheet?

[martindwilson]

to sum all a1 on sheets 1 to 4 use
=SUM(Sheet1:Sheet4!A1)
if you have different sheet names look here
http://www.bettersolutions.com/excel...N620422111.htm

[alansidman]

SUM ALL SHEETS

To Sum, say cell A1, on all Worksheets in your Workbook. With this method, all new sheets that are added to the Workbook are included in the SUM. Here is how;

Add a new Worksheet to you Workbook at the far right. To do this select "Worksheet" under "Insert" on the Worksheet Menu Bar. Then left click on this new Worksheet name tab, holding down the the left mouse button drag to the far right and release.
Name this sheet (double click the name tab) "Spacer" (although any name will do).
With "Spacer" being the active sheet, go to Format>Sheet>Hide.
Repeat steps 1 to 3 above, but this time name the Worksheet "Start " and drag it to the far left.
On the Worksheet you wish to have the result shown on enter: =SUM('Start :Spacer'!A1)
Add any number of new Worksheets, enter some numbers into A1 of any Worksheet and it will be included in the SUM. Move the Worksheets order around, Delete sheets etc and the SUM function still includes all Worksheets.

If you have concerns that a user may unhide/delete/move the Worksheets "Start & "Spacer", go to Tools>Protection>Protect Workbook (ensure "Structure" is checked), supply a password (optional) and click OK.