More Adult Logic

There's a certain confusion caused (in some of my students) when they're told "now change all the subtraction to addition [of the opposite]." Sometiems those all-important last three words are sort of missed.
I've been having some success with explaining that we can't really change subtraction to addtion. If we could, I would be a millionaire - every check I wrote would add money instead of subtracting it.
But if we change the number to balance it out, then we haven't changed what we're doing, we're just changing *how* we're doing it to a more advanced way that lets us do more advanced things (*that's* the part that doesn't flow well yet).
So, when you do change that minus to plus, you have to also change the number to its opposite.
For the hands-on learners, teach your hands that it will always mean two marks. (See "bam-bam" method below :-)).

The other "what old knowledge is getting in your way" part of this is explicitly stating that "addition doesn't always mean add any more. We're much more sophisticated now."
Now, can we have a hurricane here and a few days off - but keep the power on, please! Marge doesn't have the generator yet... - so I could develop a nice little Flash lesson for that?