How do I teach my students to THINK instead of MEMORIZE?

[theresacrider]

I teach high school physics (1st year). I have some extremely bright students in my classes, and many of them are doing well in my class. However, one thing I have noticed is that they like to look at examples and memorize them instead of trying to understand how the problem works and solving it using a logical process. The result is that if they see something slightly different than the example, they panic and sya they don't know how to do it when they DO! They eventually work it out with a bit of encouragement. But how do I get them to understand that they can do this, and think outside the box? It's a struggle to get them to think for themselves every time I give them a new assignment! Advice from teachers who have been at it longer than me would be appreciated!
An example of what I'm talking about: I gave them a problem that involved changing 23 km into meters. Instead of thinking, "1 km is 1000 m, so what do I do?" They just thought, "which way do I move the decimal point? A lot of them ended up with answers of 0.23 meters, and it never occurred to them until I pointed it out that that just didn't make any sense because kilometers are bigger than meters! These kids are juniors and seniors - and I'm concerned about how to combat years of memorization and regurgitation, and teach them actual problem solving skills!

[~* 50bTuFf CoOkEe**]

mkae it simple like a story or something. Don't read right out of the textbook!!!