Problems with a Case Statement

I have a case statement I am trying to build using checkboxes to show what stage a particular report is sitting on (based on the completion of child record Tasks). The last line would the default result if none of the others are true.

First problem is that it's telling me the second line is expecting a text value, and the last problem is how to get it to return the default value if the previous criteria aren't met.

Case(
ToNumber([Report Ready for Posting]) , 1 , "Posting" ,
ToNumber([Report Ready for Final Review]) , 1 , "Final Review" ,
ToNumber([Report Ready for 2nd Review]) , 1 , "2nd Review" ,
ToNumber([Report Ready to Review]) , 1 , "1st Review" ,
ToNumber([Report Ready to Process]) , 1 , "Report Processing" ,
ToNumber([Report Ready for LFee]) , 1 , "License Fees" ,
ToNumber([Report Payment Data Received]) , 1 , "Payments" ,
[# of Completed TSK]<2 , "Not Started")