Students investigate basic properties of common materials by observing, folding, crinkling, tearing, stretching, and then strength-testing strips of paper, plastic, and aluminum foil. The class emphasizes planning fair tests so each material is tested the same way.

1. Prepare equal-size squares of plastic, paper, and aluminum foil for each group; provide extra felt or fabric for teacher demonstrations.
2. Discuss what a property is and how testing can reveal properties beyond sight and touch.
3. Model each test with a felt square: fold, crinkle, tear, and stretch; have students describe what they observe.
4. Distribute one of each material to students and an activity sheet; students first record observations by looking and touching.
5. Guide students to perform the Fold Test on each material and record how the fold behaves after release.
6. Guide students to perform the Crinkle Test and note differences in texture and ability to smooth back out.
7. Guide students to perform the Tear Test using similar force for each material and record relative ease of tearing.
8. Guide students to perform the Stretch Test using similar force and note which materials stretch and which do not.
9. Review the idea of a fair test: same size samples, same procedures, same forces as closely as possible.
10. Demonstrate a simple Strength Test with a felt strip bridging two equal-height books; predict how many coins it will hold.
11. Have students cut equal strips of paper, plastic, and foil; place across two equal-height books and add pennies one at a time at midspan until failure; record counts.
12. Compare class data to identify strongest, weakest, and in-between materials; discuss why results differ based on structure and thickness.
13. Conclude by connecting properties to uses and why different materials suit different products.

PROPERTIES of MATERIALS for Kids - Strength, Rigidity, Elasticity, Flexibility and More - Smile and Learn - English:

📄 Testing Materials to Learn About Their Properties - ACS: https://www.acs.org/education/resources/k-8/inquiryinaction/second-grade/chapter-1/testing-materials-to-learn-about-properties.html

• Test additional materials such as cardstock, wax paper, or fabric using the same procedures.
• Change strip width or span length to see how geometry affects strength.
• Replace pennies with small washers or paper clips to compare results with a different load type.
• Try controlled-force tearing or stretching with spring scales to make measurements quantitative.

• Use child-safe scissors with supervision when cutting strips.
• Keep coins and small items away from mouths; supervise younger students to prevent choking hazards.

• Why must all samples be the same size and tested the same way? (To make a fair comparison so differences are due to the material, not the test.)
• Which test best revealed differences among the materials and why? (Answers will vary; many classes find tear and strength tests show the clearest differences because they involve failure.)
• Why did paper often hold more pennies than foil even though foil is metal? (The foil sample is much thinner, while paper has interlocking fibers that add stiffness and support at similar thickness.)
• If you doubled the strip width without changing materials, what would you expect in the strength test? (It should hold more weight because a wider strip spreads the load over more material.)
• How do these simple tests connect to choosing materials in real products? (Engineers match material properties like strength, flexibility, and thickness to what a product needs to do.)