The MOD function in T/SQL is actually the % which is the modulo operator.
From Books OnLine:
<pre>Returns the remainder of one number divided by another.
SELECT 38 / 5 AS Integer, 38 % 5 AS Remainder ;</pre>
The ROUND function takes a number with a decimal place and rounds it to the nearest while number.
<pre>SELECT ROUND(123.9994, 3), ROUND(123.9995, 3)</pre>