In a message of Thu, 05 Mar 2009 15:19:52 MST, Charles Cossé writes:

On Thu, Mar 5, 2009 at 2:52 PM, Laura Creighton <lac@openend.se> wrote:

...

In a message of Thu, 05 Mar 2009 12:51:40 MST, Charles Cossé writes:

The interesting question (to me at least) is whether he would be willin g to rewrite a + b + c as a + c + b

and then if he would be willing to rewrite a + b as a - (-b)

Yes, I confirmed that it was definitely due to having been repeatedly told the simple rules for order of operations; he observed that "there was something to be multiplied" and believed that he couldn't proceed until he had carried out that multiplication, which immediately led to a gridlock situation for him ... and he would have been okay rewriting like you did there since there was no multiplication. Guess it's just one of those many things that you don't realize kids think until you come across it ... and then it's a surprise

Charles

I'm teaching 10 and 11 year olds here in Sweden, but over the summer holidays or on weekends in optional classes. I am always curious as to how the rest of the world teaches things. Can you ask him for a favour for me and see if he would be willing to accept that: 82 + (15 * 10) - 51 is the same as (15 * 10) + 82 - 51 or if the * is really stopping him cold. And thank him very much for me for answering my question, if he is willing. Laura