VALUE

From AgileApps Support Wiki

The VALUE function converts a text string with numbers into a number. Since field values are typically returned as strings, this function is used to convert the value to a number.

Syntax
VALUE(string-expression)
The string-expression is usually a field name, but may be more complex
Return
Number
Example
VALUE(priority)
Returns 1, 2, 3, etc. depending on the priority-field setting