Estimate of Cost:  Assuming you have computers with Internet access and printers, it should be fairly inexpensive.
1. Art Unit:
    paper -- $.50/student; pencils -- $.10/student;  rulers -- $5.00/class; triangles -- $10/class.  For sculptural extension: foam core -- $5/student; X-acto knives --$25/class; hot glue guns -- $15/class.

2. Nature Unit: rulers (see above); protractors --$15.00/class; compasses--$25.00/class.

3. Math Unit: rulers (see above); protractors (see above) ; compasses (see above).