Whether you want to work out **some simple calculations** or compute the **eigenvalues and eigenvectors of a matrix** there is probably a free online calculator to do the job for you!

**WolframAlpha** is so powerful (and not only for Mathematics) it deserves **pages of its own**. There are **several links** available and also **slideshows** to help you learn to use WolframAlpha. (WolframAlpha is still entirely free to use and so useful for teachers and students, though a new Pro option is now also available).

Using **WolframAlpha widgets** makes it possible to set up widgets for repeated use, older students for example need to solve absolute value equations.

When I find a new online calculator I like I include it in another blog: **Mathematics Calculators and Tools **so that the collection is together.

To highlight a few of the calculators I have used recently. For students studying quadratic equations **this calculator** which shows the use of the quadratic formula from **Math Warehouse** is very useful as it shows full working on how to use the formula.

There are **numerous other calculators available from Math Warehouse**.

The graphing calculator I return to again and again is the **Desmos graphing calculator**, for example I was recently studying the modulus function with my sixth form students, looking at modulus equations and inequalities **a picture** speaks a thousand words! (Just type y=abs…)

When marking the Further Mathematicians’ Decision Mathematics paper I found **Stefan Waner’s Simplex Tool** very useful,

The tableaus are shown in full.