All math content is generated via a third-party tool called MathJax. This tool uses various markup languages to generate math formulae, including MathML. Screen reader support for MathJax and MathML is strong but, depending on the screen reader you use, you may need to switch to a different browser or download an additional plugin so that the screen reader reads the content in an expected manner.
If you use JAWS on Windows
JAWS supports MathML content out of the box when using Internet Explorer, Chrome, or Firefox. We strongly recommend using Google Chrome as your browser but, if this is not possible, we recommend using Internet Explorer instead. You do not need to install any third-party software applications or plugins.
The Freedom Scientific website contains a tutorial that introduces MathML: Using MathML with JAWS.
If you use NVDA on Windows
NVDA does not, by default, read MathML content. To do so, you need to install MathPlayer 4 (a free application) on your computer. Once this application is installed, NVDA will read out all mathematical content. We strongly recommend using Google Chrome.
If you use VoiceOver on macOS
VoiceOver supports MathML out of the box when using Safari. You do not need to install any additional plugins or addons. Be aware that math content may not be announced by VoiceOver when using Mozilla Firefox or Google Chrome on Mac OSX, so we strongly recommend using Safari where possible.
The MathJax website includes a complete list of keyboard explorer commands that you can use to access math content.