Calling a sub (subroutine) [VBA]

sub somesub( arg_1 as single, arg_2 as single)
  msgbox(arg_1 & " * " & arg_2 & " = " & arg_1*arg_2)
end sub


sub call_somesub()

   somesub 5,6
   call somesub(7,8)


   ' Parantheses not allowed in following line:
   '   somesub (5,6)

   ' Parantheses required in following line:
   '   call somesub 7, 8

end sub