I'm guessing that this is what you want. Although I got a check sum of 7.
I deserve at least half of the credit for helping you with your homework!

PAVB, I don't think that you are too old. Since I work at a university
I can take classes. So I end up in computer classes with people half
my age. I would say that they are too young.

Code:
SYS@devdb AS SYSDBA> DECLARE
  2  	v_string  VARCHAR2(2000) :=  REPLACE('001 0072053 60 3716796', ' ', '');
  3  	i	  PLS_INTEGER;
  4  	digitSum  PLS_INTEGER := 0;
  5  BEGIN
  6  	i := 1;
  7  	WHILE i < length(v_string)
  8  	LOOP
  9  	   digitSum := digitSum + substr(v_string, i, 1);
 10  	   i := i + 2;
 11  	END LOOP;
 12  
 13  	digitSum := digitSum * 3;
 14  
 15  	i := 0;
 16  	WHILE i < length(v_string)
 17  	LOOP
 18  	   digitSum := digitSum + substr(v_string, i, 1);
 19  	   i := i + 2;
 20  	END LOOP;
 21  
 22  	DBMS_OUTPUT.PUT_LINE('The check digit is: ' || MOD(digitSum, 10));
 23  END;
 24  /
The check digit is: 7

PL/SQL procedure successfully completed.