Monday 25 February 2013

More on place value...

The students are working so very hard to understand addition and place value. 

I am finding however that many of them wish to use the traditional algorithm while they have little understanding of place value and the how-much-ness of a number. E.g. If I say 28 - your child needs to understand that the 2 is not two but twenty - or 2 tens. 

Children need endless opportunities to use numbers in authentic and meaningful ways so that, when they are ready to use a traditional algorithm, they will see immediately if their answer is unreasonable. E.g. the answer to 38 + 13 should be approximately 50 since 38 is close to 40, and 13 is close to 10, and 40 + 10 = 50. 

Many children will make the following mistake:
38 +
13   
411     and will not recognize that there is a problem here.

Practise addition with your child at home WITHOUT using the traditional algorithm. Instead, ask him/her to show you the other three ways we have learned to add. 


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