Create accessible equations

Reading and especially writing mathematical equations by people who use screen readers has been thwart with complications and incomplete solutions. MathML has represented perhaps the most effective means of presenting equations. Tools for writing MathML efficiently remain limited and not readily available to screen reader users.

MathType, available on a subscription basis, can be used to produce fully accessible equations as both MathML for use in HTML pages and as equations in MS Office products.  A significant limitation is that writing equations is inaccessible to screen reader users.

 An important step has been made with recent changes to the Equation Editor in MS Word and advances in both the NVDA and JAWS screen readers.  Note that full access to reading equations only applies to Word in Office 365 and not to non-subscription versions.

What doesn’t work

Avoid using the following document types to ensure compatibility with screen readers:

• PDF files, as these contain equations that cannot be read by screen readers
• MS Word and PowerPoint documents, which can usually be read by screen readers but provide poor navigation.
• Webpages that display equations as images with alt text descriptions. These provide a poor user experience as the alt text description cannot be paused, rewound etc. Long and/or complex equations are therefore very difficult to read in alt-text format.

What does work

Websites that display equations using MathML provide a better user experience for all users. Equations displayed in MathML:

• Can be read by screen readers (with navigation inside equations)
• Are unambiguous (e.g. division means division, not forward slash)
• Are easily enlarged using magnifier software
• Display more effectively on tablet and mobile devices.
• Can be copied into other applications (e.g. MS Word) for notetaking.

While some browsers natively support MathML (e.g. Firefox and Safari), Chrome and Chromium based browsers (e.g. Microsoft Edge) do not. This problem is usually overcome by including MathJax support in webpages. MathJax works in all major browsers and displays equations written in either MathML or LaTeX (which MathJax converts to MathML on-the-fly).

Canvas includes MathJax support, though users with accessibility needs are advised to use specific browser/screen reader combinations to provide the most accessible experience.

Equations may be added to Canvas using either the Math Editor (recommended) or HTML Editor (MathML only). You can create accessible equations in Canvas using:

1. Math Editor Basic View – this would be used for simple equations.
2. Maths Editor LaTeX View – this would be used for complex equations.
3. MathML code entered directly in the Canvas HTML editor (not recommended as the MathML cannot be easily edited in Canvas)

Equations entered using any of these methods will be displayed as images with LaTeX alt-text and MathML for screen readers. No specific browser or additional software is required to view equations entered in the Math Editor.

Equations written in the Equation Editor can be presented by both above screen readers via synthetic speech and/or electronic Braille output.  Significantly, with sufficient knowledge, a person using a screen reader can also write equations.  Equations can be input with either Unicode or LaTex notation.  The method needs to be selected in Preferences, discussed further below. 

Access to the Equation Editor

It can be accessed from the Insert tab of the Ribbon. Some commonly used equations can be selected.  With relevant equipment, equations can be drawn by hand.  Or, the focus of this document, the Equation Editor can be opened, and an equation entered.  More direct access to the Editor is through the keyboard shortcut, alt+=.

Equations can be displayed as professional or linear.  Keyboard shortcuts are control+= and shift+control+= respectively.  Alternatively, right click the equation and select the required option.  While professional would normally be used, linear is helpful for editing.

Equation Editor options

With the Editor open, the Equation Tools tab of the Ribbon is available.  Within Options a choice of Unicode or LaTeX entry can be selected.  Unicode is the default but, especially in an academic environment, LaTeX seems a good choice.

Another setting option is to copy an equation as MathML or as a linear equation.

Putting an equation into an HTML page

Copying as MathML allows the equation to be included in an HTML page.  However, the MathML code provided by Word includes the mml namespace on each element.  This is only relevant to XHTML files and must be removed if used on an HTML page.  Furthermore, full access to MathML on XHTML pages is limited to NVDA in Firefox.  Therefore, copy the code into a text editor such as Notepad and do a global replace of “mml:” with nothing.  The code can then be placed in the HTML page.

Pasting existing equations into Word’s Equation Editor

This can be helpful when wanting to convert existing LaTeX equations into an accessible format.  Copy the LaTex equation from a text editor (not from within Word), open the Equation Editor and paste the equation.  The equation will be in linear format.  Press control+= to convert to Professional.

Reading equations with screen readers

When encountering MathML on a web page or a MathType or Equation Editor equation in Word, screen readers will present the equation and announce, “Math”.  The user can issue a command to the screen reader which allows inspection of the equation in fine detail.  Commands and facilities vary between screen readers, and it is strongly suggested that screen reader documentation be consulted.