Project Code Name: Baked Alaska

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Teacher's Guide



In this project the student will use the history list in an attempt to solve the Koenigsberg Bridge problem. The problem was one of the first major problems in the area of mathematics called graph theory. Graph theory is somewhat related to the theory of computer networks. The problem can be stated as follows:

    As in the diagram below there were seven bridges in the old town of Koenigsberg, at that time in Prussia, but now in present day Latvia. Starting at any point, can you travel across every bridge exactly once without crossing any bridge twice?

Konigsberg Bridge Problem

Pick a starting point on an island or side of the river!

The students will not be able to complete a circuit of the bridges without crossing some bridge twice. They can view their progress by looking at the history list.



If a student claims to have solved the problem correctly, review the history list with them and point out the error. The game was created using only HTML, it was necessary to keep track of the direction of bridge crossings. Items listed as

  • brg1.htm, or brg1d.htm

both represent bridge 1. The second case, brg1d.htm indicates that it was crossed going downward or south.

A famous mathematician by the name of Leonard Euler (pronounced Oiler just like the football team) proved that there were no solutions to the problem, i.e. every path fails.



Let the students come to the conclusion that it is impossible. Challenge them discover why it can not be done. You have probably seen clickable maps on websites. This game is not a clickable map in the usual sense. The game instead is created using a series of icons inside a table. The game could also be created using clickable maps. Not every browser currently supports clickable maps.

You and you students can create your own clickable maps by using this project as a template and changing the icons. See, for instance, the chapter on Templates.

  • Step 1

    Use the game by showing your students how to open local files on the floppy disk. You may open the game directly or simply open the student worksheet.



  • Step 2

    Show the students how to access the history list on the browser. Have the students experiment with hyperlinks and the history list until they are comfortable using it.

  • Step 3


    Have the students open the file kbp.htm in the directory of your choosing using their World-Wide Web browser. See Step 1 above.

  • Step 4


    Let the students experiment by following the directions and clicking on the various positions in Koenigsberg. Each bridge crossing can be viewed in the hyperlink window before the student crosses it.