I've been obsessively using the TI-nspire as a discovery tool in my classes these last 2 weeks. In geometry, we just started parallelograms, and I wanted them to explore the 5 properties of parallelograms, and it worked great.
One extra thing that I'm excited about is that I had them hold up their closed fists, and I asked them to put up a finger for every syllable of "parallelogram". Five! Ohhh! Five properties. So. Every time they discovered a new property on the calculator, I had them run through the list so far and tick off a new finger for the newly discovered property. We did this until we got through all 5 properties. Woot! Memory tool. Hopefully, they'll remember that there are 5 and parallelogram has 5 syllables, and they can recite all the properties:
1. parallel opposite sides
2. congruent opposite sides
3. congruent opposite angles
4. supplementary adjacent angles
5. diagonals bisect each other