To give the kids a taste of what light sources are, we tried a fun activity using their oil pastels on black paper. Most of the kids got the concept through this guided project, which made for an excellent springboard to the next part.
Once the kids got this down, I had them make pumpkins. First, I showed them how to draw a good, quality pumpkin. I heard that some of them liked that so much, they went home and drew pumpkins everywhere. My kids are so cute. Next, I told them to draw a large pumpkin toward the bottom, and a smaller pumpkin toward the top of their black paper, in white oil pastel (this was for depth!). They were also to draw a white frame around their paper. They were to color the sections of the pumpkins in the same way they just finished the sphere, and then put on a stem. After that, they were told to draw three horizontal jagged lines to divide the background evenly. I had them use a dark green color for the bottom, a middle green for the next, then a light green section, and a light blue for the top. Lastly, they added the shadow in black. Not only were the kids impressed with their own work, but their parents were, too!