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 two-dimensional 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

10-15 rubber bands

One ruler

 

For the class:

PowerPoint: Shapely Spider Webs

 

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 two-dimensional 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 3-10 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:

·     Paper-Pencil 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

Paper-Pencil

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 Paper-Pencil 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 web-based 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