SQL Round Function

Question

round(45.923,-1) gives a result of 50. Why is this? How it is calculated?

(sorry guys i was mistaken with earlier version of this question suggestin

Answer 1

It doesn't for me on MySQL:

mysql> select round(45.923,-1);
+------------------+
| round(45.923,-1) |
+------------------+
|               50 |
+------------------+
1 row in set (0.00 sec)