Applied Science - Science and Math (2C) Post Lab
 OBJECTIVES: Comparing symmetry and patterns. Discovering tessellations. VOCABULARY:  geometry  pattern  polygon  symmetry  tessellations MATERIALS: Pattern Blocks worksheet Students create tessellations.
 BACKGROUND: Tessellations are an assemblage of regular polygons that do not overlap and creates an arrangement or repeatable pattern.  The word “tessellate” is derived from a Greek derivation which refers to the four corners of the tiles in a mosaic.  There is different levels of understanding tessellations.  In elementary school it is important to understand that a polygon is shape that has 3 or more straight enclosed sides.  A triangle is a polygon.  A tessellation can be considered  a pattern of polygons. The limits of a tessellation are that the polygons are regular.  The object of this exercise is to see how many different tessellations students can discover.  A pattern is not limited to just polygons.  So, a tessellation is a specialized pattern.   A unit cell can be found in tessellations.  Then the unit cell is repeated to give an overall  pattern or design. PROCEDURE: Discuss with students that tessellation can be seen all over.  The sidewalk is a series of rectangles that are concrete.  A chain fence is a series of hexagons or pentagons.   See if students can tell you more tessellations that they see around them.    You are  giving the students the "power" to observe.  This type of project will also allow you to discover which students have an "artistic" eye.    Students should do the worksheet before they use they use the pattern blocks.  This will help students think of a design before they actually do the activity.  Students will soon realize that there are constraints to geometry.  You just can't put a triangle against a pentagon without constraints on the overall design.    Students should work in teams to build different tessellations.    Remind them that a pattern is repeatable.   Go over the symmetry of each of the pieces.  The triangle has a three-part symmetry, the pentagon has a five part symmetry, and the square has a four part symmetry.  Use the term "tessellation" to refer to the geometric mosaic that the students are creating.  Remember if they are using a circle in their pattern, it is not a tessellation.