Unit Plan 8 (Grade 3 Science): Magnet Engineering Challenge

Focus: Use magnets to solve a real-world design problem (move, retrieve, or sort objects) by applying ideas about magnetic forces and cause-and-effect.

Grade Level: 3

Subject Area: Science (Physical Science • Engineering/Design)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session

I. Introduction

In this unit, students apply what they’ve learned about magnetic forces to an engineering challenge. Working in small teams, they define a simple problem that can be solved with magnets (e.g., picking up paper clips in a “spill,” moving objects in a maze, sorting metal vs. nonmetal items). They generate multiple solutions, build and test prototypes, and then improve their designs based on what they observe about magnet strength, distance, and materials.

Essential Questions

• How can magnets be used to solve real problems, like moving or sorting objects from a distance?
• What cause-and-effect relationships do we see between magnet strength, distance, and the motion of objects?
• How do engineers use criteria and constraints when they design with magnets or other tools?
• Why is it important to test, record data, and improve our designs instead of stopping after the first idea?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Describe and investigate magnetic forces acting on objects at a distance and identify which materials respond to magnets.
2. Define a simple design problem that can be solved with magnets (movement, retrieval, sorting) and list clear criteria and constraints.
3. Generate and sketch two or more possible solutions that use magnets, then select one to build based on the criteria.
4. Plan and carry out fair tests of their magnetic device, keeping key variables the same while changing one thing at a time.
5. Use their test results to improve their design and explain, in student language, how magnetic forces helped solve the problem.

Standards Alignment — 3rd Grade (NGSS-Aligned)

• 3-PS2-4 — Define a simple design problem that can be solved by applying scientific ideas about magnets.
  • Example: “Design a tool that uses magnets to pick up paper clips from a ‘spill’ without using your hands.”
• 3-5-ETS1-2 — Generate and compare multiple solutions based on criteria and constraints.
  • Example: Sketch two different magnet tools and compare how well each could move or sort objects.
• 3-5-ETS1-3 — Plan and carry out fair tests with controlled variables to identify improvements in designs.
  • Example: Test two versions of a magnetic retrieval tool at the same distance and record how many objects each can pick up.

Success Criteria — Student Language

• I can describe what my magnet device is supposed to do and what makes it a successful solution.
• I can sketch and explain at least two possible design ideas before building my final magnet device.
• I can plan and run a fair test, where I keep some things the same and change just one thing.
• I can use data from my tests (how many objects, how far, how fast) to improve my design.
• I can explain how magnetic forces helped my design solve the problem.