Build a Better Pencil

This investigation uses a pencil to introduce the idea of planning and evaluating designs. The familiarity of this object will allow students to propose a variety of ideas on how to improve it. The small scale of this design challenge allows for a greater range of solutions that can be carried out using everyday classroom tools and materials. By trying to solve a problem they have experienced while using a pencil, students become "engineers." They try to design and make a better pencil. The success of this lesson is not in the building, but in experiencing on a beginning level the process engineers go through as they attempt to solve a practical problem. This lesson will frustrate teachers and students who fixate on "getting the right answer," but it is a valuable experience. The lesson writer repeatedly emphasizes that the purpose is to give students experience in the engineering process.

Lesson Variations

Blooms taxonomy level: 
Applying
Extension suggestions: 

Extensions:

  • There are a multitude of classroom problems that students encounter each day - for instance, problems created by being too short - can't erase the top of the blackboard, wobbly chairs, jackets falling out of cubbies, sandwiches getting squished in lunchbags, shoes coming untied, etc.
  • Have students brainstorm an everyday problem that they would like to solve. Students should record this problem in pictures and/or words, as well as a possible solution to the problem. Students may still need some help in identifying those problems that are both interesting to them and within their capabilities. (Benchmarks for Science Literacy, pg. 49)
  • Choosing small-scale designs will allow students to actually build what they have planned. However, students who propose large-scale designs should be encouraged and recognized for their creativity. Those designs that are impossible to build in the classroom can offer valuable opportunities for addressing the idea of constraints.
  • After students have determined what problem they would like to solve and a possible design solution, they should determine whether it is something they "can do now" or "can't do now". Students should defend their answers. (This may need to be done verbally.)

Helpful Hints

Materials:

Materials will vary, but should include:

  • Post-It® Notes
  • unsharpened pencils
  • scotch tape
  • masking tape
  • clay
  • scissors
  • glue
  • rubberbands
  • styrofoam
  • empty spools
  • erasers

References

Contributors: