Learning Intention: Students will understand how muscles work in pairs and be able to explain their function.

Introduction: 1. Begin by asking the students if they remember the name of the muscles. 2. Ask if anyone knows how muscles work. 3. Explain that in this lesson, they will learn about how muscles work in pairs.

Main Activity: 1. Show a PowerPoint presentation or a short video clip that explains how muscles work in the arm and how they work together. 2. Provide each student with a cut-out of an arm bone and a split pin. 3. Instruct the students to attach rubber bands to the split pin, representing the muscles. 4. Allow the students to experiment with moving the split pin and observe how the rubber bands (muscles) are moving. 5. Ask the students to explain what is happening with the muscles. 6. Higher ability and middle ability students should write an explanation of how the muscles are working in pairs. 7. Lower ability students should draw a picture to demonstrate their understanding. 8. If split pins are not available, students can draw a diagram instead.

Resources: - PowerPoint presentation or video clip - Split pins (or paper clips as an alternative) - Rubber bands - Tape