NUMBER(1,-2): Variable with a scale of -2 can only hold values like 100,200,300... up to 900. : Number « PL SQL Data Types « Oracle PL/SQL Tutorial

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2. PL SQL Data Types
3. Number

SQL>
SQL> SET ECHO ON
SQL> SET SERVEROUTPUT ON
SQL>
SQL>
SQL> DECLARE
  2    hundreds_counter  NUMBER(1,-2);
  3  BEGIN
  4    hundreds_counter := 100;
  5    LOOP
  6      DBMS_OUTPUT.PUT_LINE(hundreds_counter);
  7      hundreds_counter := hundreds_counter + 100;
  8    END LOOP;
  9  EXCEPTION
 10  WHEN OTHERS THEN
 11    DBMS_OUTPUT.PUT_LINE('That is as high as we can go.');
 12  END;
 13  /
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That is as high as we can go.

PL/SQL procedure successfully completed.

SQL>
SQL>