Sheets 1 & 2 are now called Invoice-1 & Invoice-2

Invoice-1: Cell G27 =SUM(E22:E26)
Invoice-1: Cell G37 =SUM(E33:E37)
(of course, the amounts in E cells change with each invoice I create)

In Invoice-2 (cell G26) I need to put the total of cells G27 and cell G37
from Invoice-1. Can anyone advise as to how I can do this?