You can summarize part of an estimating while leaving other parts expanded.
For example, you might do this if you need to get subcontractor bids for division 2 and 5, but divisions 3 and 4 are finished.
To do this:
Double-click the row header (the little box all the way to the left of the spreadsheet) at the level you want to summarize.
Double-click in the row header next to the Group phase 3000 and 4000. This summarizes 3000 and 4000 to a single line on the spreadsheet while leaving 2000 and 5000 at the item level. You can selectively summarize like this in any sort sequence.