By this point the class will become very awe-inspired by the discrepancy in sizes from the extremes of Jupiter and Pluto. The best has yet to come. Constructing the Sun. Because of the size difference, the most convenient solar fabrication is a flat 2-dimensional representation and constructing it in two halves to be taped together later. Start by laying out half of the cardboard ton the floor and taping the edges together with the duct tape. Because duct tape does not accept tempera paint very easily this will be the back side. Refer to
Carefully turn the cardboard over and tape the front side with the wide masking tape. The radius can be drawn by finding the center on the long edge and using the tape measure as a pivot, one person holds the tape at 198.8 cm.(or at 92 3/8 inches). Another person can carefully hold a pencil at the end of the tape measure and walk it around the cardboard to end up with a semi-circle. Cut the cardboard with a razor and the class can now paint the cardboard with the yellow paint. Repeat this process with the rest of the cardboard to make up the second half of the Sun.
Hopefully, there is a place somewhere on the premises where these two halves can be taped together and displayed. Ultimately, the Solar System should be hung for all the school to see, because it is quite an awesome spectacle to behold. When one sees the incredible size difference in our Solar System between the Sun and the Earth, it can be a very sobering experience.
If it is possible, display the material in a high area. Then, have the class write a brief description of what they did. Also, a chart explaining the scale distances these planets would have to be from this miniature Sun in order to match these sizes. This has proven to be an exceptional way to motivate the rest of the school as a stepping stone for additional ideas about the Solar System and Astronomy.
As an extension to this first lesson it would be very revealing to the class to take a field trip with these planetary models and drop them off by the side of a straight and remote road at the scale distances. This experience would make it more concrete to the students the incredible reaches of our solar system.
Extensions to lesson:
include more information about Earth and Moon relationship
more about the individual characteristics of each planet
more about meteors, comets and asteroids
do some daytime solar and lunar telescope viewing
time a favorable planetary viewing with a local astronomical society
calculate the speed of the field trip bus with the speed through the solar system