# MathJax fails when rendering long digit strings on iOS

This answer formats properly on Safari 5.1.7 on Lion, but on the iPad with iOS 5.1 the √2+6/√2=2.638958433764... does not format properly and I only see the MathJax, i.e. \$\sqrt{2}+\frac{\sqrt{6}}{2} = 2.638958433764...\$

Safari on iOS tends to mark long strings of numbers as a phone number and inserts a link so that you can call the number. That inserts HTML into the math string, and MathJax won't process it since it doesn't think Math should contain HTML.

One solution is to insert {} in the middle of the number (e.g., 2.638958{}433764...) so that iOS won't think it is a phone number. Another would be to use a fake CDATA comment so that iOS will leave the contents alone:

$<!--[CDATA[ \sqrt{2}+\frac{\sqrt{6}}{2} = 2.638958433764... ]]-->$


Either should resolve the problem for you, I think.

• That's pretty annoying. I'd much rather see a site-wide solution rather than having to edit each problematic answer. Do we need/want phone number detection on the math sites? If not, can we just get <meta name="format-detection" content="telephone=no" /> inserted into the global header? – Old Pro May 21 '12 at 17:13
• @old the proper "site wide solution" is for Apple to better detect phone numbers. – Jeff Atwood May 23 '12 at 5:27
• @Jeff, why not change what is under your control rather than suffer your site to mis-render on millions of devices? Especially when the change is so minor. Later, when Apple sees the wisdom of your solution, it will be easy for you to revert. – Old Pro May 23 '12 at 7:26
• Math.stackexchange.com could add the HTML meta described here: stackoverflow.com/a/4056764/7061 – Thomas Andrews May 27 '12 at 1:44
• @Thomas, that is exactly what I suggested in my first comment. – Old Pro May 27 '12 at 2:01
• Whoops, missed that. @OldPro – Thomas Andrews May 27 '12 at 2:02

There is a MathJax site-wide solution that can be used, assuming that you never want this Safari behavior on math.stackexchange.com. See the answer for an HTML meta tag to disable IOS auto formatting: https://stackoverflow.com/a/4056764/7061