Hello stack overflow members, I have an issue I'm dealing with and am not sure how to fix it. So I have this SQL code:

```
SELECT ABS(SUM(TO_CHAR(a1.test_amount, '99999.00'))) AS "Test Amt"
FROM test a1
WHERE a1.test_id = '102434'
AND a1.test_detail_code IN ('2334','2335','2336')
AND a1.test_period = '201501'

```

All I'm trying to do is convert the `a1.test_amount` into a format with two decimal places. When I do `TO_CHAR` with the following, it works fine. 

```
SELECT TO_CHAR(1450, '99999.00')
FROM dual
----------
1450.00

```

That leads me to believe it has something to do with the `SUM`? Any help would be greatly appreciated!