NUMBR
Converts a string to its numerical value.
    Syntax
NUMBR(String)
String is a string or a formula which
        returns a string. All characters except 0 through 9, '+', '-','.' and 'E' are ignored. If
          String cannot be converted to a number, the result is
        undefined.
Examples
This example returns -7.8:
NUMBR('-7.8')
      
This example returns -6.6:
NUMBR('-6A.A6A')
This example is undefined:
NUMBR('-- 7')