# You must remember this - Mnemonics can take maddening memory matters out of maths

21st October 2011 at 01:00

The other day I re-introduced the idea of co-ordinates to my advanced skills group. How to remember that (2, 3) means two across, three up, rather than the other way around? I reached into my own mathematical childhood and recalled the phrase which echoes across the years still - "You go IN the house, then UP the stairs." Daniel immediately stuck his hand up with a glint in his eye - "What if you are a burglar?"

He made me reflect that one's person's aide-memoire could be another's mental stumbling block. But are there not times when we need a crutch for useful facts? As educators we prefer memory based on understanding, but if that's tough to achieve, might a piece of mental jogging be allowed to come to our rescue?

It is Mnemosyne, the Greek goddess of memory, who gives us the word "mnemonic", and I remember one of my first. Aged 11, I recalled that "lt;" stood for "less than" by telling myself that "lt;" looked quite like a squashed "L".

Years later I twigged that "lt;" had a small left hand end, and a big right hand end, so the notion the symbol was trying to convey was embedded in the mark itself. It was its own mnemonic.

I asked: in statistics, what does "negative skew" mean? It means the hump of the distribution is to the right, and the tail is to the left. Positive skew means the hump is to the left and the tail is to the right. Come up with a mnemonic for this, please.

Claire suggested "positive" and "port" (= left) shared the same two starting letters. Angus offered that the second letter of "plus" is "l" for "left". But then, if you remember these incorrectly as "a positively skewed distribution has a TAIL to the left", you are in trouble. James offered this improvement - imagine a p on its side, bubble up, and a g on its side, bubble up. Yes!

Jonny Griffiths teaches at Paston College in Norfolk

What else?

Resources

Try some of Jonny Griffith's own RISPS resources, which are a big hit with maths teachers on TES and highly recommended by advanced skills teacher Craig Barton

In the forums

Teachers discuss the use of the grid method for long multiplication and share innovative ways to digitise maths solutions using tablets and whiteboards.

Not a subscriber? Find out more about our subscription offers.
Subscribe now
Existing subscriber?
Enter subscription number