How to avoid circular error

[Ura]

I need to sum a column of numbers, one of which is a function of the total.
This is a classic circular error but there must be a way to iterate the sum
until the error is negligible. I don't understand the Excel help notes and
they don't work when I try to follow them.

 

[Ken Wright]

Tools / Options / Calculation Tab / Check the Iterations box and it will
work, but note that inadvertant circs will now no longer be flagged for you
by Excel.