I teach elementary. With my 5th graders I provide each table with a box and
a hole on the top, a flashlight and usually an orange or a grapefruit. The
students put the flashlight in the hole on the box and a piece of fruit
inside the box. The light beams on the fruit and they can easily see the of
values.. They arrange themselves at the table so everyone has a good view.
The light in the box becomes the sun/light. The children then begin to draw
and shade. After using pencil and charcoal, they move onto one color of
watercolor paint and repeat the process of creating the values.