User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.0.3705) Build Identifier: User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.0.3705) When I add 1.89 and 1 (1.89 + 1) using javascript, I get the answer 2.8899999999999997. But if I add 1.89 and 10, I get 11.89. This happens every time, but only with certain numbers. Reproducible: Always Steps to Reproduce: 1. var num = 1.89 + 1; 2. alert num; 3. Actual Results: I get a message box with the value 2.8899999999999997 Expected Results: Given me 2.89 :-)

This really does depend on your definition of correct :-) Mozilla is following the appropriate standards here--the issue centers around trying to represent base-10 numbers in a computer that does base-2 math. See the references in the duped bug for more info. *** This bug has been marked as a duplicate of 20140 ***

Marking Verified Duplicate. Note that JavaScript is not the only language in which this behavior occurs. Also C, C++, Java, etc. Here are some more references: bug 42134 "JavaScript should be more lenient comparing (==) floats" bug 129300 "Error in javascript internal routine : parseFloat" bug 154103 "arithmetic error in JavaScript Engine" bug 160173 "Error de punto flotante al sumar en JavaScript" bug 186563 "Number.toFixed: loss of precision" bug 190303 "Javascript floating point calculation" Good web references: http://developer.netscape.com/docs/manuals/js/core/jsref15/number.html#1200964 http://www.merlyn.demon.co.uk/js-maths.htm