I have a SQL error below when I run my PHP SQL code:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE useid = 8' at line 1
mysql_query("UPDATE free_ebook SET math = $assign_math WHERE useid = $newuserid;")or die(mysql_error());
The math field is int(10), and useid is also int(10).
Looks like the field name should probably be userid, not useid.
Alternatively, try enclosing the values in single quotes, like this:
"UPDATE free_ebook SET math = '".$assign_math."' WHERE useid = '".$newuserid."';"
or even
"UPDATE free_ebook SET math = '{$assign_math}' WHERE useid = '{$newuserid}';"
On the topic: mysql_query() is deprecated, you should be using the PDO extension. It's easy (maybe easier!) to learn and a lot more secure:
Are there good tutorials on how to use PDO?
http://wiki.hashphp.org/PDO_Tutorial_for_MySQL_Developers
http://net.tutsplus.com/tutorials/php/why-you-should-be-using-phps-pdo-for-database-access/