Simplifying a formula

Hi this is my first post here and apologise if its not clear'

So im setting up an accounts database for my shop (ive included a small relevant part of it below).

What im trying to achieve is to simplify the formula I use for calculating sales.

E F G H I J K

Item Sale Profit Earnings Week
Price 1 2 3

1 3.99 3.44 1.72 1 1 5
2 2.50 2.14 1.07 2 1 2
3 4.99 4.34 2.17 1 2 0

Total 13.98

At the moment the 13.98 is got from:

=(I4*E4)+(I5*E5)+(I6*E6)

This multiplies the number sold per week and the item sales value. This works ok in my example but my spreadsheet will have over 25,000 items over 4 sheets. So rather than set up a huge formula im looking for a way to simplify it.

Thank you.

I dont know why the formatting has been changed it looks fine when i try to edit it........

Thank you Martin this worked a treat.

I already know how to specify sheets etc in formulas so thank you.

Another quick question, when copy and pasting a formula for example:

A1=A2+A3

Pasting it into B1 automatically makes it:

B1=B2+B3.

and so on with C1 onwards

How do I copy a formula where say A2 must be a constant? so when i paste formula into B1,C1 etc the formula is automatically

B1=A2+B2 or C1=A2+C2

thank you again...

Sorry im new to formulas and excel but I also have another questions.....

How could I simplify this formula@

=SUMPRODUCT(Rings!K4:K6,Rings!F4:F6)+SUMPRODUCT(Bracelets!K4:K6,Bracelets!F4:F6)+SUMPRODUCT(Watches!K4:K6,Watches!F4:F6)+SUMPRODUCT(Beads!K4:K6,Beads!F4:F6)+SUMPRODUCT(Earrings!K4:K6,Earrings!F4:F6)

I thought removing all the SUMPRODUCT's and bracketing the formula would have worked but apparently not

=SUMPRODUCT((Rings!K4:K6,Rings!F4:F6)+(Bracelets!K4:K6,Bracelets!F4:F6)+(Watches!K4:K6,Watches!F4:F6)+(Beads!K4:K6,Beads!F4:F6)+(Earrings!K4:K6,Earrings!F4:F6))

Any ideas please??

Thank you again Martin,

ok as I explore deeper into excel I have another question:

I need to have a forumla in a cell that when a number typed into the same cell it keeps the forumla and only displays the result

for example

A1=x-B1
B1=x-B1

now rather than have to edit 'x' in every formula (it varies) I wondered if there is a way that I can just type the value of x into cell-A1 and it would enter it automatically into the formula and display the result??

Hope that makes sense.

Thank you for your quick response DG, shame but guessed as much.

Lastly I know this can be done but im using Excel 2010 which looks great but is much more difficult to use than 2003. I want to freeze the top menu cells so that as I scroll down through figures the menu headings are always visable??

Thank you