A family of Microsoft word processing software products for creating web, email, and print documents.
You need to check the 'calculate on exit' property for the formfields in cells 1 & 2. In cell 3, you don't need a formfield. You can use a formula field instead, coded as:
{IF{=Cell2} > 0 {=Cell1/Cell2*100 # "0.00%"}}
Note1: Instead of the Cell2 and Cell2 references, you can use actual cell references, like A1 & A2. Also, the above field construction avoids divide-by-zero errors.
Note2: The field brace pairs (ie '{ }') for the above example are created in the body of the document via Ctrl-F9 (Cmd-F9 on a Mac) - you can't simply type them or copy & paste them from this message.