Observing sun spots
Use the telescope that you made in a last experiment. Set it up so that it points directly at the sun and focus it so that a clear and bright image of the sun is formed on a piece of white cardboard placed a short distance from the eyepiece lens. If sun spots are there on the surface of the sun you may be able to observe them as small dark spaces of irregular outline on the image. Caution. Do not look at the sun by the telescope, unless your eyes are protected by a dark glass filter.