Q: Numbers 3.5 Yosemite

I need more than a collection of Numbers 3.5 Help Files to help me understand the "theory of operation" of this beast, helpful though those help sheets are.

Separately, I'd like to know how I find the location of Numbers Template files. Do they have a special filename extension, are they "invisible" files which we must "uncloak" before we can see them?

Tack to the File Hierarchy/ies:

I'm particularly interested in "cross-over nomenclature" from prior worlds (Lotus 123, XL, OpenOffice

Even more particularly, what is the hierarchy of "numbers 3.5" files?

Package? (or file?)

Worksheet  or is it Workbook?

Spreadsheet

Sheet

Table

Can I draw on data in "sheets" in separate "files" (or Workbooks/worksheets) if I have two or more Files/Packages/Worksheet/Woorkbooks open so they could do the RAMa-dama ding-dong sharing through RAM?   Or is that not possible, and we're just supposed to add "sheets without end" on one file/package/whatever?

Like this exercise:  Middleman Wholesaler  is in control of the spreadsheet. He has 56 manufacturers, for whom he sells products to 87 customer-retailers. And he needs to track the sales (and commissions) every month for every manufacturer and ever end-client.  Can I have 56 Manufacturer sheets I can summarize with one master sheet in a day-by-day/week-by-week/month-by-month sales report?  And ditto the retailers--87 sheets, one for each retailer? And one summary sheet?  Same thing with generating invoices, using this already-captured information.

And of course, some of the 56 manufacturers proffer  a dozen or more separate "product lines"--say Macaroni and cheese, pre-mixed peanut butter and jam...and then of course there are the Return Materials Approval #s (RMAs) and such--Or is this beyond Numbers' capabilities?

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