This video is about how to ‘rationalise the denominator’ – which is just a way of changing the bottom of a fraction to a whole number – and gives a few examples:
5 divided by 3√2 becomes 5√2 / 6
18 divided by √3 becomes 6√3
Like many of these exercises, in isolation, they appear to be fairly irrelevant – it’s only when you need to manipulate equations in higher levels, that they can be useful. Most ‘rationalise the denominator’ questions appear on non calculator GCSE maths papers (including Edexcel, AQA, OCR and Educas), and are approximately grade 6+. The questions are usually 2 – 4 marks.
Please do try some of the questions in the additional posts listed below – with a little practice learning how to rationalise the denominator can be fairly straightforward.
This series of 3 minute math is designed as a quick reminder for some of the main topics. I hope they help to provide a focus and a way forward. If you need any more detail please search the site or contact me – always pleased to answer any questions!
Here’s some additional posts, that might be of interest: