1) I got this sheet with 30 or 31 plans each - yes, one for each day. How do
I insert automatic numbering so that I number Plan 1 as page 1, Plan 2 as
page 2 and so on?

2) After I insert automatic page numbering, how do I print all the plans
without opening one by one?

3) Whenever I open this sheet, it comes the popup window saying that there
is an error in a formula. There are 70 or 80 formulas in each plan. How can I
find the wrong one without inspecting one by one?

Thanks in advance.