If you're teaching light physics to middle school kids, you can show what happens to optical images when light passes through a pinhole aperture. Students love this experiment and it's very simple to setup. For homework, get your students to construct a simple ray diagram showing how the rays of light enter the pinhole viewer and form the image. You can also incorporate a lesson on how the human eye does the same.
Do you have any recommended science experiments using inexpensive materials? Did you find these ones useful? Let us know what you think.