# Understanding SURDS - essential Mathematics

Where does the word SURD come from?

Around 820AD the famous Persion Mathematician al-Khwarizmi saw irrational numbers (namely numbers that cannot be written as fractions) as "inaudible numbers".

The LATIN for "inaudible" is "SURDUS" and so from this comes our use of the word SURD.

We now use SURD for a number which we cannot find the square root of.

The aim of this web-page is to collate together revision guides, worksheets and videos to help you understand SURDS and thus develop your Mathematical understanding in this key area.

For the moment, we have placed a number of maths revision videos to highlight our work in progress. Navigate around to your specific area using the menu above

Our videos are hosted on YOUTUBE and can be accessed by clicking the images.

Rationalising Surds, how to simplify fractions to make the denominator real

Simplifying Surds - make the number in the square root as low as possible

Multiplying Surds - how to multiply two of more surds together

Surds and Brackets - how to extend your skills involving brackets to include surds