SQL> declare
  2    l_datum date;
  3  begin
  4    l_datum := sysdate * 4;         --> error is here
  5  end;
  6  /
  l_datum := sysdate * 4;
             *
ERROR at line 4:                       --> these lines say what's wrong
ORA-06550: line 4, column 14:          -->
PLS-00306: wrong number or types of arguments in call to '*'
ORA-06550: line 4, column 3:
PL/SQL: Statement ignored


SQL>