The purpose of creating graphics by plotting
points is to use built-in Scheme functions to understand how drawing commands
work. By studying patterns, these examples then can be used in future
lessons to create variable functions.

This process is used in the teaching of
algebra, which starts in the primary grades with arithmetic. When
a student learns to add, first blocks and fingers are used as examples
to understand the process. Students then build on this primitive
operation by adding multiple times.

In algebra the constant numbers become
variables represented by a letter. In programming that letter can
be a descriptive identifier for the unknown value. Functions can
be written which use variable data in the solution of problems. Multiple
examples can be used to test the function. A design recipe is used
to facilitate the data analysis and planning of the solutions.

Coordinate points are lists of two points,
the X and Y values. These lists are called positions (posn) in DrScheme.
Recursive functions create loops to repeat a process. In this module
student are only USING built-in functions. They are creating examples
which can be turned into functions in more advanced programming.
This is step 2 in the design recipe in How To Design Programs.

Graphic programming support the TEKS and
TAKS objective for problem solving found in all curriculum areas.
Special emphasis in algebra and geometry is working with functions, patterns
and coordinate points.