I downloaded a worksheet and got a file without extension(named:download); I renamed the file to .pdf and opens fine. Would be better if I get a file name of wo

I downloaded a worksheet and got a file without extension(named:download); I renamed the file to .pdf and opens fine. Would be better if I get a file name of worksheet-type.pdf I also want to add - it would be nice to see the target age of kids based on the selections or select worksheets based on age, narrowing down to particular type. fyi- the layout on the pdf is clean (and very kid friendly)