Adjusting Revenue to exclude tax

Hello,

I am trying to figure report on gross ticket sales net of tax (which is included in the price of the ticket)

I was trying this formula: SUM((Total Paid Amount)-((Total Paid Amount/1.0925)*.0925))

SUM(([Total Ticket Paid Amount])-((([Total Ticket Paid Amount]/1.0925)*.0925)))

I keep getting a Function Syntax Error: Unexpected token '.' in Encloses Numeric Expression definition.

What am I missing?

Thanks :-)