Spaghetti Bridge Building

In this project, students draw upon their explorations of geometry attributes and design to build bridges that they designed in week #6 of SMART Math.

Time: 40 minutes
Materials: Raw spaghetti, glue, masking tape, scotch tape, scissors, cardboard (for foundation of bridges).

Getting Started:
*Hand out students' "blue print" drawings (from week #6). Students who were absent should be encouraged to do a quick sketch before starting to build.
*Students should be encouraged to work in pairs, but may work alone.

The challenge

*Explain to students that they have been hired (because of their solid mathematical abilities) to construct a bridge, using the designs they created last week.
*Remind them of the challenge: To design and build the least expensive and strongest bridge that spans a distance of 5 inches, using only the materials on the list.
*Review the materials available.

Measurement and budget

*Stress the measurement component of this activity by explaining that the cost of each inch of spaghetti is $100. Use the comparison of purchasing lumber at a lumber yard....lumber (or steel) used in REAL bridges is very expensive.

You may choose to introduce the idea of scale and structure here, encouraging students to imagine their bridges as "life size" and how each inch of spaghetti would then translate into a much bigger length, and a much more expensive material!

*Explain that each of their bridges is limited by a strict budget of $20,000 At $100 per inch, can students figure out how many inches of spaghetti they can use in their bridges?
Answer: 200 inches of spaghetti per bridge.

*Get started on the building! Encourage students to create, make mistakes, start over, and think mathematically!
*Remind them at intervals how much time is remaining in their SMART period.

Finishing up:
*If space allows, store bridges somewhere in classroom so that students may share their work with one another. If space does not allow, students may take bridges home, or give to Bess to store in the SMART room.

Extensions:

*Students can name their bridges, decide where their bridge will be built (over a river or a canyon or.....) and create drawings to that effect.

*Strength testing may also be conducted, using uniform weights, such as paperclips or pennies. Make sure students understand that their bridges will break in the process, as they determine how much weight it will hold before collapsing. This exercise emphasizes process rather than product, and can be great fun!

Working with spaghetti

*Working with the spaghetti is challenging, and interesting in it's ability to hold tension. Students will discover the "breaking point" along the way, and can compare this to their previous work with straws.
*Students will be tempted to nibble on the raw spaghetti, and although this is fine, you should remind them that at $100 dollars per inch, it's a rather expensive snack! ...And, any spaghetti that they eat reduces the quantity they have available to build the best possible bridge.