Good afternoon.

I am new here looking for some guidance please.

While working on a cash flow page of Excel, I am gettig a strange
result.
Attempting to add a few cells together I entered the formula =SUM(B4:F4),
press enter and I get a date 18/03/1900, to try and fix it, I deleted all
and in 3 different columns I entered 100, 50, 50 then in the "G" I put the
above formula and got 19/07/1900.

I started with an old sheet and saved as, then deleted evrything from
it, but also lost the formula, so I pulled the original to copy them across,
the first one I wrote was =SUM(A4:E4), a being the column where the
date had been deleted from and got a date appear. If I put the formula
anywhere else on the sheet, it works properly.

I know very little about Excel, but I was shown many years ago how to
write formulas and how to move around a page, but that is all that I know.

Can somebody tell me what is wrong or what I am doing/not doing that
is causing this.

Mike.