Rounding Mechanism to nearest 0.05

Question

I would like to solve rounding mechanism by using php4,5.2 and below (not 5.3) Currently I am doing 0.05 rounding, something like this page:

http://www.bnm.gov.my/in

Answer 1

Thank you @mauris for the solution to solve my problem on Malaysia GST rounding mechanism. It also works in SQL.

DECLARE @tempTable AS TABLE(Number Decimal(20,4));

INSERT INTO @tempTable VALUES (89.90),(89.91),(89.92),(89.93),(89.94),(89.95),(89.96),(89.97),(89.98),(89.99)

SELECT Number, round(Number * 2, 1) / 2 AS 'Rounded' FROM @tempTable