Numbers runs very slowly after installing Yosemite ?

Question

iMac (20-inch, Early 2008)
2.4 GHz Intel Core 2 Duo
4 GB 800 MHz DDR2 SDRAM
ATI Radeon HD 2400 XT 128 MB
After installing Yosemite, all my Numbers spreadsheets respond only very slowly (e.g several seconds to click open a cell or scroll to a new line).
I have updated to OS X 10.10.2 with no improvement. Has anyone else had this? Can anybody tell me how to fix it?

Answer 1

I have stumbled on the apparent solution to the slow Numbers issue. When I upgraded old Numbers files to the latest issue of software, and opened them from the hard drive (instead of via the original dock icon) everything worked normally, and the new dock icon [ 3.5.2 (2118) ] remained in the dock when I dropped the old one into the Trash (removing it from the dock). Incidentally, I noticed that for each Numbers file that I upgraded, the file size was roughly doubled.
Being a non-technical user I was a bit surprised that the upgrade to Yosemite didn't take care of this sort of issue, but perhaps there's someone in the community who can enlighten me ?