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Preparation:
Gather the necessary materials, set up the microscopes and computers, and prepare one computer to project in front of the class.
Note: These general preparation instructions will not be included in future activities, as they are appropriate for all the activities in
this guide.
Procedure:
1. Have students work in pairs or small teams to complete the activity.
2. Toward the end of the activity, when the class is ready, project a view of salt crystals at 40X magnification and have students
measure the size of the image.
3. Lead a discussion on the size of the salt crystal, the magnification of the crystal, and the size of the image.
• The 4X objective results in a 40X magnification; the 10X objective a 100X magnification, and the 40X
a 400X magnification.
• The salt crystals are 3-dimensional, despite how they appear under the microscope.
• The scale at which an image is viewed (mini-screen, computer screen, projector) doesn't change the
magnification of the microscope.
Assessment:
Have your students prepare a summary of the various magnifications and their implications. What is the magnification using each
lens of the digital microscope? What is the field of view at each magnification? What is gained by going to a higher magnification?
What is lost? How does magnification relate to image size?
Understanding Magnification and Scale (continued)
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