Pythagoras and Dyscalculia

This approach:

  • Uses a calculator.
  • Uses just one single approach for all problems (long side or short)
  • Reduces the number of steps by rooting and adding in the same step.
  • Keeps to an absolute minimum, the need to compare sizes, because Dyscalculia makes this challenging.
  • Uses a mnemonic to recall the steps.


Normally in a problem involving Pythagoras, you are given 2 of the sides of a right angled triangle and asked to find the third. You need to Root the Add of the Squares (R.A.S, end of PythagoRAS). Always key in the larger number first….wpid-20150422_133239.jpg

This will give the answer 8.0622..

but Perhaps You Takeaway (PYThagoras) so mouse back to the plus (+) and change it to a take away (-)… and this gives  5.7445..

Now it’s decision time – using the picture, which answer looks most sensible, 8.0622 or 5.7445? The length of the 3rd side in this example is clearly longer than 7 so the correct answer is 8.0622.


#Mathscpdchat about #dyscalculia this evening September 2nd 2014

This event has been organised by the NCETM. It is a regular discussion hour for Maths Teachers but this topic is bound to attract parents, sufferers, and other interested Tweeters – they are welcome too. Teachers don’t have a monopoly on good ideas!

Can I take part?

Yes. If you tweet between 7 and 8 this evening using the tag #mathscpdchat then your tweet will automatically form part of the discussion. Sign into twitter then click here to take part.

Can I listen in, without being a Twitter user?

Yes you are welcome. The window below will display the tweets in real time. (But joining twitter is really easy – why not create your own ID and join us?)

More about the NCETM discussions – click here to read more

The discussion – a window on twitter

Dyscalculia and Dyslexia

A word about Dyscalculia and Dyslexia

According to Brian Butterworth, Dyscalculia is a severe lack of awareness of number, coupled with great difficulty in performing arithmetic tasks. Research and Diagnosis in the UK is still at a relatively early stage, I can recommend the writing of Jan Poustie (herself a sufferer) as an excellent start for the reader wishing to be able to “see the world through Dyscalculic eyes”, and for practical suggestions of how to cope.  ** the best book – Mathematical Solutions Part B is available from the author  (see comment below)

Butterworth  suggests that about 4% of the population may “have dyscalculia”. Looking at the bigger picture, it is clear to anyone working with maths education that a far larger proportion of the population struggle with aspects of Maths, and do not thrive on the traditional approach.

I prefer to see “number blindness” as a spectrum, on which some people are extremely fluent and comfortable with number, to the extent that they seem truly gifted, others struggle painfully, and the majority are somewhere in between, often feeling that they are worse than average, even if they in fact are right in the middle. I start work with every student assuming that they are “number-blind” until I see evidence to the contrary. This helps me to remember that, compared with a Maths teacher, most people are relatively number-blind. Unless you immerse yourself in number as much as a teacher probably has, you may not recognise high powers of two, multiples of large primes like 17, etc etc.

Many Dyslexics struggle with Maths, perhaps because of the extremely complicated processes required to carry out the high-end of arithmetic operations, such as pen and paper division. I am privileged to have worked with a handful of severely dyslexic students, who were very articulate about their learning styles and helped me to experiment with how to express Mathematical reasoning in a way that they could make sense of.  Poustie indicates that individuals may well be experiencing some degree of Dyslexia and Dyscalculia, together.

Labels such as Dyslexia and Dyscalculia are only helpful if you have some strategies for coping with them, and I tend to focus on the learner, the Maths, and the strategies, and not worry too much about labels.

I welcome feedback, please use the reply box.