I am ready to replace my diary and netbook with an ipad. The only thing that's needed is spreadsheet. Now I understand that the ipad has 'numbers' which is a lite version of number son the mac which I use endlessly. I have some queries, would be glad if anyone could answer: 1) Can I store spreadsheet files on the ipad? Or do I need to store them online and everytime I need to edit, I have to download them? 2) Can I edit those same spreadsheet files? 3) does numbers for ipad support formulae (simple additions & subtractions) Cheers!