What they will notice about this is enough to get them started, because the number of squares they will now see illuminated by the flashlight beam will be very different. Think about graphing or circling the beam where it hits the paper. Turn the room lights down lower and ask them to repeat the investigation. Suggest maybe that one group just hold the flashlight above their graph paper and the other tilt their paper. Hopefully, someone will exclaim that the tilted paper is not as brightly lit.
Light is made up of little bits of energy.
Then ask students if there is any difference between tilting the board and tilting the flashlight. So, when the Sun is lower in the sky, it is like a tilted light source. Or in other words, on parts of the Earth tilted away from the Sun, the Sun's light is not as intense as on regions directly facing the Sun. At this age level, students are ready to really grasp this concept and build on it. By encouraging their math skills, ability to abstract, and by getting them to make connections, we hope to bring together the big picture for them.