SQL & PL/SQL :: Date Stored As Number

I have a table

CREATE TABLE TEST
(
X NUMBER(8),
SNUM NUMBER
)
SET DEFINE OFF;
Insert into TEST (X, SNUM) Values (20100409, 1);
Insert into TEST (X, SNUM) Values (20100317, 1);

[Code]...

For some reason, column x is a number data type, but the data is actually date.

My aim:

1. select the maximum of the dates stored in column x (in numeric data)..for a given snum.

2. check if it is within 3 days range and return 1 or 0

My program

CREATE OR REPLACE FUNCTION f_chk (in_num number)
RETURN NUMBER
IS
v_chk NUMBER;
v_max_dat number;
BEGIN
SELECT COUNT (*) INTO v_chk

[Code]....

I have following assumptions, correct me if I am wrong:

SELECT max(x) INTO v_max_dat FROM test WHERE snum = in_num;

1. The above will actually give me the maximum date for a given snum (correct result), since the data is stored in yyyymmdd format, it does actually picks up the maximum date (stored in number format) for a given snum ... or should i use to_date to convert it to date and declare v_max_dat as date ?