A teaching Place Value tip by Philippa Bodien
Head of The Dyslexia Unit
Jumeirah Primary School
Dubai
United Arab Emirates

 I was asked by a parent to assist her yr 3 daughter understand number. 

A few sessions with Dienes blocks and a vertical abacus and she had a better idea of the units we were discussing;

No concept of exchanging 10 ones for 1 ten and so on though. No understanding of why number is recorded in places: unit, ten, hundred, thousand. After about three lessons we had got to writing a four digit number and then me asking her what each number stood for. That was ok.

Then I asked her to add or subtract units or tens or hundreds or thousands up to 9. No thought of counting up and down a number line or using her fingers ("I was told not to use my fingers"... guess that comes from mental maths in the numeracy hour).  Just puzzled.  Used fingers better.  (We can call fingers what we like - they can be units or tens or hundreds...)  Then she tried to write 70 as 70 in the tens column instead of just writing a 7.

So I wrote out each place value in full - say 6000, 400, 20, 1 and compared it to 6421.  I asked her what the difference was since we could say it in the same way.  Then why.  Then showed her how the full numbers overlaid 6421, but told her the zeros were sneaky and they were hiding.  Lightdawned.

I had tried the same idea using cards to overlay but this had not clicked with her.