Introduction:

Prior to beginning the lesson: (1) Cut out and laminate Vocabulary Cards for display in the classroom; (2) Photocopy The Strength of a Magnet (1 per student). (Allow 25-30 minutes for instruction time.)

Group Size: Partners

Learning Objectives:

Students will be able to:

• Understand that magnetic strength varies according to the size of the magnet.
Materials:

Vocabulary Cards (see attachment), The Strength of a Magnet (see attachment), horseshoe magnets, bar magnets, disk magnets

Procedures:

1. Display Vocabulary Card "magnetic force". Ask students: Who remembers what this means?
2. Hold up the three types of magnets. Tell students: Each of these magnets has a different magnetic force. Some magnets are stronger than others.
3. Ask students: Which magnet do you think is the strongest? Why do you think that? Give students time to share their ideas.
4. Divide students into pairs. Distribute one horseshoe magnet, one bar magnet, one disk magnet, one paper clip, and two copies of The Strength of a Magnet to each pair of students.
5. Direct students to fill in their hypothesis.
6. Show students how to line up their magnet at the edge of the experiment line and how to test each magnet’s strength. Direct students to mark the point on the line where the magnet stops attracting the paper clip.
7. Give partners time to complete the experiment.
8. Ask students: What did you find out? Which magnet is the strongest? Which magnet is the weakest? Why do you think that?
9. Direct students to answer the conclusion questions at the end of the experiment.
Modifications: For students with special needs, allow them to dictate answers for the teacher to record, or provide one-on-one assistance for students’ to write answers.

Assessment:

Monitor students’ participation for understanding. Circulate classroom and ensure students are writing correct answers.

Benchmark or Standards:

National Science Education Standards K-4.1 Science as Inquiry – As a result of the activities in Grades K-4, all students should develop:

• Abilities necessary to do scientific inquiry.