Implementing accessibility skills: Equations

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As with images, you must take special care to ensure that the equations in your course materials are accessible to anyone using text-to-speech or other assistive technology. Otherwise, the equations will be skipped completely or will be rendered in a garbled format; either way, the student misses critical information.

Learn how

Learn how to make equations accessible.

Typing simple equations

If it’s an equation that you can type easily, you can do that (instead of, for example, using images). Take care to render everything correctly. For example, if the equation is a-squared plus b-squared equals c-squared, be sure to use superscripts to indicate the squares: a2 + b2 = c2. Don’t just type “2.”

Similarly, don’t use an x to indicate multiplication.

On a PC, you can select the ALT key while typing 0215 to create a correct multiplication sign.
On a Mac, you’ll need to use the Insert Equation function and then find the multiplication sign.

For slightly more complex equations, you can use an image and then add alternative text. The more complex your equation, the more you will want to outsource that description to a supported math language.

Math languages such as MathML or LaTeX can be directly recognized by screen readers as equations. (Notice that the word is spelled “latex,” like the rubbery material, but it’s pronounced lah-TEK.)

Alt text for equations

If you’ve opted to add alt text to your images of equations, write out that alt text as you would speak the equation out loud in class or in a recorded lecture. You can type numerals rather than spelling out numbers, but spell out mathematical operations and Greek symbols.

The following example is adapted from Accessible Text and Math from the Northwestern University School of Professional Studies:

A trigonometric equation

Alt text for this equation would read as follows:

Sine squared is equal to one-half times the quantity (1 minus cosine of 2 theta) over 2. Cosine squared is equal to one-half times the quantity (1 plus cosine of 2 theta) over 2.