truncate number

[atarrqis]

CR11 & Oracle
I have a number field, GL.yearmonth where the data looks like:
201101
201102, etc.
I have a paremter field - (?EndPeriod) where the user enters the ending yearmonth for the report.
I need to truncate this to just the first 4 digits and then compare it to a number field, GL.year, which is 4 digits and looks like:
2010
2011, etc.
I can't figure out how to truncate and make it still appear as a number field. If I use left('(?EndPeriod)', 4) Crystal treats it like a string.

 

[lbass]

tonumber(left(totext({?EndPeriod},0,""),4))

-LB

 

[atarrqis]

Thank you!