) means 'out of one hundred
Per Cent (Cent=100).
To find n percent (n%) of x use the formula
Used in mathematics
Overheard from a 12-year-old discussing how useful her claculator is:
"You press one button to convert it [a fraction] to a percent and then another to convert it to a decimal."
Perhaps the single most depressing thing I've ever heard. No, wait. That would be the cashier that asked "what's 10% of $3.00?"
See Why do middle school math classes need calculators?