Skip to content

Earth's Magnetism and CompassesActivities & Teaching Strategies

Active learning works well for this topic because students need to manipulate magnetic materials and observe directional behavior to grasp abstract concepts like field lines and pole alignment. Hands-on activities help students move beyond memorizing that a compass points north to understanding why it does so in relation to Earth's magnetic field.

Primary 4Science4 activities25 min45 min

Learning Objectives

  1. 1Explain the origin of Earth's magnetic field as a result of its molten core.
  2. 2Describe how a compass needle aligns with Earth's magnetic field to indicate direction.
  3. 3Analyze the function of Earth's magnetic field in protecting the planet from solar wind.
  4. 4Compare the magnetic north pole and the geographic North Pole.

Want a complete lesson plan with these objectives? Generate a Mission

Ready-to-Use Activities

25 min·Pairs

Demo: Build a Simple Compass

Stroke a sewing needle with a bar magnet 50 times in one direction. Float it on a cork in a water bowl. Observe as it aligns north-south. Have pairs predict and test in different spots.

Prepare & details

Explain why the Earth acts like a giant magnet.

Facilitation Tip: During the Build a Simple Compass activity, remind students that the needle must be magnetized before floating it on water to ensure proper alignment with Earth’s magnetic field.

Setup: Groups at tables with case materials

Materials: Case study packet (3-5 pages), Analysis framework worksheet, Presentation template

AnalyzeEvaluateCreateDecision-MakingSelf-Management
45 min·Small Groups

Stations Rotation: Magnet Field Lines

Prepare stations with bar magnets under paper sprinkled with iron filings, plotting compasses, and bar magnet interactions. Groups rotate every 7 minutes, sketching observations and noting alignments.

Prepare & details

Describe how a compass works to indicate direction.

Facilitation Tip: When running the Magnet Field Lines station, have students trace the field lines with markers before moving to the next station to reinforce visual memory of magnetic patterns.

Setup: Tables/desks arranged in 4-6 distinct stations around room

Materials: Station instruction cards, Different materials per station, Rotation timer

RememberUnderstandApplyAnalyzeSelf-ManagementRelationship Skills
35 min·Pairs

Outdoor: Compass Treasure Hunt

Mark a schoolyard course with directional clues using compasses. Pairs start at a point, follow bearings like '45 degrees northeast for 10 steps.' Discuss deviations from magnetic north.

Prepare & details

Analyze the importance of Earth's magnetic field for life on Earth.

Facilitation Tip: For the Outdoor Compass Treasure Hunt, assign roles like 'navigator' and 'recorder' to keep all students engaged and accountable during the activity.

Setup: Groups at tables with case materials

Materials: Case study packet (3-5 pages), Analysis framework worksheet, Presentation template

AnalyzeEvaluateCreateDecision-MakingSelf-Management
30 min·Whole Class

Class Demo: Earth Magnet Model

Suspend a bar magnet from string to mimic Earth's field. Use multiple compasses around it to show deflection. Students record angles and compare to classroom magnetic north.

Prepare & details

Explain why the Earth acts like a giant magnet.

Setup: Groups at tables with case materials

Materials: Case study packet (3-5 pages), Analysis framework worksheet, Presentation template

AnalyzeEvaluateCreateDecision-MakingSelf-Management

Teaching This Topic

Teaching this topic effectively starts by connecting abstract concepts to tangible experiences. Avoid using static diagrams alone, as students need to interact with materials to internalize how magnetic forces operate. Research suggests that combining modeling with real-world navigation tasks strengthens spatial reasoning and retention of magnetic principles.

What to Expect

Successful learning is evident when students can explain in their own words how Earth’s molten core creates a magnetic field and how this field affects a compass needle. They should also demonstrate the ability to use a compass to navigate and discuss its real-world applications with confidence.

These activities are a starting point. A full mission is the experience.

  • Complete facilitation script with teacher dialogue
  • Printable student materials, ready for class
  • Differentiation strategies for every learner
Generate a Mission

Watch Out for These Misconceptions

Common MisconceptionDuring Build a Simple Compass, watch for students assuming the compass needle points to the true geographic North Pole.

What to Teach Instead

After students build their compasses, have them compare their needle direction to a labeled map showing magnetic declination for your location. Ask them to adjust their path to account for the difference between magnetic north and true north.

Common MisconceptionDuring Magnet Field Lines station, students may think Earth’s magnetic field is created by a solid bar magnet inside the planet.

What to Teach Instead

Use the spinning liquid model at this station to show how molten iron currents generate the field. Ask students to sketch the movement they observe and explain how it differs from a fixed bar magnet.

Common MisconceptionDuring the Earth Magnet Model class demo, some students may believe Earth's magnetic field has no impact on daily life.

What to Teach Instead

After the demo, have students simulate how the magnetic field deflects 'solar wind' balls using magnets. Then, facilitate a discussion linking this to the protection of satellites and the creation of auroras.

Assessment Ideas

Exit Ticket

After Build a Simple Compass, provide a worksheet with a diagram of Earth’s magnetic field. Ask students to label the poles and draw a compass needle at three different locations, explaining why the needle aligns as shown.

Quick Check

During the Magnet Field Lines station, ask students to hold up their traced field line diagrams and compare them to a reference image. Quickly circulate to check for accuracy and discuss any discrepancies as a class.

Discussion Prompt

After the Outdoor Compass Treasure Hunt, pose the question, 'What might happen to our technology if Earth’s magnetic field weakened?' Guide students to connect this to the role of the field in protecting satellites and power grids.

Extensions & Scaffolding

  • Challenge early finishers to design a short obstacle course where teams must use their compasses to navigate between points, adjusting for magnetic declination using a provided map.
  • For students who struggle, provide a pre-labeled compass diagram to guide their needle placement during the Build a Simple Compass activity.
  • Deeper exploration: Have students research how animals like birds or sea turtles use Earth's magnetic field for migration, then present their findings to the class.

Key Vocabulary

Magnetic FieldAn area around a magnet where magnetic forces can be detected. Earth has a large magnetic field generated by its core.
Magnetic PolesThe two points on Earth where the magnetic field lines are strongest and point vertically downward or upward. These are near the geographic North and South Poles.
CompassA navigational instrument that uses a magnetized needle that aligns with Earth's magnetic field to show direction.
Solar WindA stream of charged particles released from the Sun. Earth's magnetic field deflects most of this harmful radiation.

Ready to teach Earth's Magnetism and Compasses?

Generate a full mission with everything you need

Generate a Mission