Authentic Assessment

Bridge Construction

Topic - Algebra - Patterns and Functions

Task - Constructing Bridges

Directions:

An engineer wants to know how to calculate the number of spans and supports needed for any length bridge constructed using either of the following two designs.

Designs One:

  1. Spans are yellow rods
  2. Supports are red rods
  3. This bridge design is build by adding supports and spans as pictured above to span any required length.

Design Two:

  1. Spans are black rod
  2. Supports are light green rod
  3. This bridge design is built by adding spans and supports as pictured above to span any required length.

Conclusions:

Describe how you would calculate how many rods would be needed to build either type of bridge for any possible size. It is okay for a bridge to extend beyond the desired length by part of a span.

 

 

(1993). Measuring UP: Prototypes for Mathematics Assessment.
Mathematical Sciences Education Board National Research Council.
Washington, DC: National Academy Press.

 

Dr. Robert Sweetland's notes