Shapely Spider Webs
Susan Cerruti, Mathematics Educator, Mathematics & Science Center
Developed with funding from the Mathematics & Science Center 
Grade/Subject 
Grade 3; Mathematics (Geometry and Measurement), Science (Scientific Inquiry) 
Major Understanding 
Identify, compare and analyze attributes of twodimensional shapes and develop vocabulary (line segment, angle, point) to describe attributes (side, corner). Measure objects using standard tools in inches and/or centimeters.

Objectives 
Identify and use centimeters and inches to measure length. 


Observe and create various polygons including, but not limited to squares, rectangles and triangles. 


Identify by name, models and pictures of plane geometric figures: circle, square, rectangle and triangle. 


Identify plane geometric figures by counting the number of sides, corners, and square corners. 


Identify and locate examples of a point, line segment and angle. 


Draw line segments and angles using a ruler or straightedge. 
Time 
Introduction/PowerPoint 
15 min 


Geoboard Webs 
15 min 


Transfer & Measurement 
15 min 


Practice 
Variable 


Closure 
5 min 


Assessment 
Variable 

Materials 
For each student: Shapely Spider Webs: Student Recording Sheet (Geoboard Grid)
For each pair of 2 students: One geoboard 1015 rubber bands One ruler
For the class: 
State and National Correlations 
Virginia Standards of Learning: Virginia Standards of Learning: Math 3 (3.14, 3.18, 3.19); Science 3 (3.1e, 3.1g, 3.4)
National Council of Teachers of Mathematics: Understand attribute of length; become familiar with standard units in customary and metric system; select and apply appropriate standard units and tools to measure length; identify, compare and analyze attributes of twodimensional shapes, and develop vocabulary to describe attributes; draw geometric objects; make and use coordinate systems to specify locations and to describe paths; find distance between points along horizontal and vertical lines. 
Instructional Strategies 
Introduction Explain to the students that they are going to be looking at pictures of real spider webs. Tell them that they are going to use knowledge they already possess and build on vocabulary they already know.
PowerPoint Show the photos of real spider webs. Have the students tell the many different shapes they see in each web. Use the power point to show new terms. Introduce vocabulary of line segment, point, angle and vertex. Show how a spider makes a web, pointing out the different shapes, line segments, points and angles. Have the students make observations, name the shapes, and find the points, line segments and angles of the various shapes.
Explain they are going to make their own web shape on a geoboard. Explain the rules and show examples in PowerPoint. Rules: Use 310 rubber bands. Put no more than 2 rubber bands on one point of the geoboard. No band should cross any other band. Your shape must be closed.
Geoboard Webs Students will work in pairs, but each will make and copy a polygon. Verify they followed the rules when creating their “web”, then they can copy the web onto the Shapely Spider Webs: Student Recording Sheet geoboard grid.
Transfer and Measurement Show students how to transfer their “webs” to the Record Sheet, pointing out the numbers on each grid, showing how to plot (3, 5). Have them use the ruler to draw straight lines between each point to finish their web. Show them how to use the ruler to measure the line segments of their shape. Then they use the same ruler to measure each side in inches (to the nearest ½ inch) and centimeters (to the nearest centimeter), and write their answer beside each line segment (side) that is measured. Remind them to use labels (in. and cm.). 
Practice 
If time, allow each student to do another polygon shape, following the rules, with less guidance. Follow the same procedures as above. 
Closure 
“What did we learn?” portion of PowerPoint One thought is that every shape designed has the same number of line segments (sides) as points and angles; every “corner” that has an angle, also has a point; you can not design a shape with a different number of sides than angles (there are the same number of points, line segments and angles). 
Suggestions for Differentiation 
· Encourage each student to make a “web” that is NOT a triangle, square or rectangle. · Have the students measure in centimeters and inches. 
Extensions 
Go to http://spiderroom.info · Anansi’s School · Spider Safari: How many types of webs can you visit? Collect real spider webs and compare their geometry. Point out the shapes you see, and any points, line segments and angles you can find.
Congruent angles and shapes: Have students match congruent rectangles, triangles and polygons, pointing out that polygons are congruent when they have matching angles and sides with the same measurements. 
Assessment 
The following options are provided for use in assessing students’ understanding: · PaperPencil Test: Shapely Spider Webs · Performance Task and Rubric: Shapely Spider Webs
The following table shows how the assessment items are related to the specific objectives. 
Objective 
PaperPencil Test 
Product/ Performance 
Identify and use centimeters and inches to measure length. 
7 

Observe and create various polygons including, but not limited to squares, rectangles and triangles. 
1, 3, 6, 7 
Yes 
Identify plane geometric figures by counting the number of sides, corners, and square corners. 
4, 5 

Identify and locate examples of a point, line segment and angle. 
1, 4, 5 
Yes 
Draw line segments and angles using a ruler or straightedge. 
3 
Yes 
Teaching Tips 
Shapely Spider Webs: Key to PaperPencil Test
Collect photos/pictures of spiders and their webs for display and discussion. 
References 
Mathematics & Science Center Visit the Center’s site to learn all that is new and happening at the Mathematics and Science Center. Register for student and teacher programs. http://mathsciencecenter.info/
MathInScience.info Visit this educational resource site to acquire webbased lessons and resources for students and teachers. http://mathinscience.info/
Mathgoodies.com Visit this site for interactive lessons on various mathematical concepts. http://www.mathgoodies.com/lessons/toc_vol1.html
Spiderroom.info Visit this special web site to learn about spider anatomy, webs, camouflage, food chains and common spiders found in Virginia. http://spiderroom.info 