Something really strange has happened to my Excel. Whether I open a
brand new workbook or use an existing one, any number I type in any
cell is divided by ten. Eg, 100 will turn to 10 and 123 to 12.3.
This does not happen if the cell is set to 'text' but any other choice;
'general', 'number' etc will cause the same mysterious chopping of the
value.
Any suggestions what might be going on?

Cheers from Ollie