The document provides instructions for an activity to explore strong shapes. Students will make shapes out of paper strips and test their strength. They will start with a square made of 4 same-sized strips and see that it collapses when pressure is applied. Reinforcing the square by adding a longer strip across two opposite corners creates a stronger rhombus shape. Students will then build cubes out of straws, predict how many coins they can support, test it, and modify their cube to make it stronger for a second test.
1. Exploring Strong Shapes Including the Elements of Thinking The PURPOSE of this activity is to discover the strength of shapes. Each student group will need: 4 manila folder strips (1”X 6”) 1 manila folder strip (1”X 9”) Punch holes with a hole punch at the end of each manila strip of paper. 4 brads www.rogersconnection.com
2. Question & Information: What shape could be made with 4 strips of the same-sized manila strips? Inference: Fasten with brads since holes have been punched and brads are included in the baggie. Concept: Four-sided polygons with the sides of the same length and right angles are called squares. Implication & Consequences: See what happens when you press on any part of the square. The square does not hold its shape when pressure is applied. What shape does it become (pick one: trapezoid, rhombus, parallelogram, icosahedron) www.rogersconnection.com
3. What would you suggest to make the square stronger? You might think of several ideas, but try this. Fasten the longer manila folder strip to opposite corners of the square. Try to squish the square together. The square holds its shape. What changed? Look at the shapes. Do you still see just one square? Assumption: What assumption can you make about the new shape? Which shape is stronger? www.rogersconnection.com
4. Testing a 3 Dimensional Shape for Strength How many straws will you need to build the cube? Follow the pictures to help you construct your cube. Fasten the corners with masking tape. When you finish building it, place a flat container on top. Predict how many pennies/washers you think your cube will hold. Continue to add pennies/washers until the cube collapses. How much weight did it hold? Try it again, but first, do something to your cube to make it stronger . Predict how many pennies it will hold now. Test your new, improved cube. How much did it hold this time? Did your idea work? Explain what happened. www.rogersconnection.com
5. Name:________________________ Date:_________________________ How did you make the 2 dimensional square stronger? Draw a picture of your strong square. Draw the shape your square became after being strengthened? Why do you think this shape holds together and the square does not? 4 th Grade - Strong Shapes Draw a picture of the strongest cube. What made it stronger than the others? This is the metal frame of a wobbly table. Draw a way to strengthen it.
