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Wednesday, November 23, 2005

Watch the board while I run through it.

Here's another reason why people don't like primary school teaching.

At school yesterday in maths the ten-year olds were learning subtraction. Quite a few of them knew how to do the standard algorithm (eg - 312 - 198 = take 10 from the 31 and make it 30 and give the ten to the 2 and make it 12 ). However, most children did not know this good old-fashioned method and certainly none of the less able children knew it.

The teacher, apparently following the national curriculum advice, taught them this method:

312 - 198

300 + 10 + 2
- 100 + 90 + 8
--------------
300 + 00 + 12
- 100 + 90 + 8
--------------
200 + 100 + 12
- 100 + 90 + 8
---------------
100 + 10 + 4

100 + 10 + 4 = 114

This would be fine if it was just put up on the blackboard to show what is really going on in the algorithm and then teach them the algorithm. But the children aren't taught the algorithm until they can show they can do the long drawn out method. For lots of children, especially the less able, writing all those numbers and keeping them in their proper columns is all just too much and they never get the hang of it. In fact some of the children who could do that bit of subtraction easily using the old-fashioned method were completely stumped when trying to write out the silly simplified method. I think they would do much better just being taught the algorithm - they'd all get there in the end. Teaching them this way, some of them never get there.

This happens every year. So when they were nine year olds they failed to get off the long method onto the short method. Now they are ten year olds they are still in the same boat. The old ways are the best, eh?

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