#6 on the Top Ten List of Household Items to Use in Your Science Classroom is:
To be honest, I didn't even consider index cards in my initial list of possible items. But there are so many ways to use them, beyond just flashcards!
Flatten an Index Card
Index Card Slides
Step Through an Index Card
An Index Card and a Cup of Water
A Penny for Your Finger
Penny in a Cup
Flip an Arrow
Water Drop Microscope
Comment on this post to be entered to win a prize box containing most of the Top Ten Items. And remember, if your comment contains an additional use (not mentioned above) for index cards in the science classroom, you'll receive a bonus entry!