using data across sheets with in a single work book

Here is my senario.

I have an expence report Excel sheet

I wish to make it a work book where I have 8 Sheets

1 Sheet for each day
1 Sheet that is printable with the details from each daily sheet.


What I need to know is how do I fill in Sheet 8 so that it pulls data from say Sheet 1 I'll give the example as such


SHeet 1:
E7
Sheet 2:
E7
Sheet 3:
E7
SHeet 8:
E7 = SH1:E7+SH2:E7+SH3:E7

and various other multi sheet cross talk

thank you