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Overview: Students use hand-held microscopes to explore microscopic worlds.
Booklink: The Usborne Complete Book of the Microscope by Kirsteen Rogers, EDC Publishing, Tulsa, OK, 1998. ISBN 0-7460-3106-8
Science Activity Link: Students use 30X hand-held microscopes to explore the micro world and make simple slides to study and preserve selected specimens.
Objective: Students will use a 30X hand-held microscope to observe common objects, make slides, record their predictions and observations, and gather, analyze, and interpret data.
Science Processes and Content: Processes-Observing, predicting, inferring, classifying, communicating, investigating, and gathering and recording data. Content-Magnification, systems and subsystems, transfer of energy, technology, structure and functions of objects, history and nature of science.
National Science Education Standards: Unifying Concepts and Processes, (2) Physical Science, (3) Life Science, (4) Earth and Space Science, (5) Science and Technology, (6) Science in Personal and Social Perspectives, (7) History and Nature of Science
Materials: Book The Usborne Complete Book of the Microscope, 30X hand-held microscopes (these are available from Delta Education, www.deltaeducation.com or Museum Products, www.museumproducts.net or Radio Shack or other companies for about $10 to $15 per microscope), paper, scissors, clear cellophane tape, and a variety of materials to observe under the microscope and make slides from--insects and insect parts, colored printed paper, feathers, fibers, foods, Velcro, seeds, hair, plant parts, onion cells, coins, sand, sugar and salt, fingerprints, water organisms, and more.
Procedure:
1. Acquire a set of 30X hand-held microscopes. They are excellent, yet inexpensive technological devices that enable children to explore the microscopic world. The microscopes are simply constructed and practically indestructable. Powered by two AA dry cell batteries, they are easy for children to use.
2. First, familiarize the children with the microscope. The on-off switch works like a flashlight. The object to be viewed must be centered in the opening at the light end of the microscope, with the microscope resting on the object. Turn the focus wheel to bring the object into clear view. Children will discover that the image is inverted but with a little practice they learn to adjust.
3. Many schools purchase a class set of the microscopes, storing them in a location convenient for any class that wishes to use them. The microscopes have the advantage of portability. They can be used indoors or outdoors. It is not uncommon to see children observing ants, flowers, lichens, tree leaves, pond water or other objects that stir their interest. The microscopes are a great curiosity builder!
4. Before you have the students begin using the microscopes, have them pick an item of their clothing--a sleeve, a trouser leg, a shirt or blouse and have them make two drawings; the first, how the object looks now with the naked eye, and the second, their prediction for what it will look like through the microscope.
5. Now show the students how to use the microscope. You may wish to have them put the AA cells in last because once their microscopes are working, interest will be so high that they will find it difficult to pay attention to what you say. After inserting the cells, have them view their clothing again and now make a drawing of what it really looks like under the microscope. Ask them to compare and contrast their three clothing drawings. Encourage the students to predict what objects will look like BEFORE they actually observe them under the microscope. Prediction and findings drawings can help them to become better predictors.
6. Now have your students go on a classroom micromania exploration in which they take approximately 10 minutes using their microscopes to observe objects in the classroom: carpets, clothing, paper, dead insects on the windowsills, and other students' hair are all fair game.
7. One high-interest activity that children enjoy is making cellophane tape slides. Fold papers in half long ways and have the children cut 5 or 6 equilateral triangles along the fold. The triangles should be about 12 to 15 mm wide at the base of the triangle (the fold). When the paper is unfolded, the triangle becomes diamond shaped. Cover one side of the diamond with a piece of clear tape. Now find an object (from among the materials brought to class) to be viewed under the microscope, e.g. the wing of a dead insect or a few grains of sand. Place the object in the center of the diamond on the sticky side of the tape. Take another piece of tape and place it over the hole, encasing the object. The children now have a permanent slide, one that can be transported easily and stored indefinitely. A variety of objects (see materials) can be made available in class to have the students construct a variety of slides.
8. Children can be encouraged to make their own page-size slide collections, recording their observations and notes on the margins of the pages. They may have pages entirely devoted to "insect parts," "things from my kitchen," "seeds," "dried foods," and other collections that might interest them.
9. Share the book, The Usborne Complete Book of the Microscope, with the class and make it availabe as a reference. Children will enjoy the microphotographs of human body parts, insects and insect parts, watery minibeasts, and unwelcome guests that live on, in, or with us.
10. The microscope is an excellent technological tool for reinforcing other curricular areas. Children can practice their descriptive writing skills while observing interesting objects such as insect eyes, human hair, and plant pollen. Sketches of objects viewed reinforce art skills. Observations of the warp and woof of natural and human-made clothing fibers can lead to exciting social studies lessons on the history of weaving and the role of the textile industry in the industrial revolution. After using the microscopes, children will be especially interested in reading about the microscopic world we live in but seldom see. Several titles sure to catch their attention include: The World of Small, Yikes!, Yuck!, and Invisible Bugs and Other Creepy Creatures the Live Within You-all referenced in the section Related Books.
11. Two other suggestions for using the microscope are to:
a. Take a micromania field trip around the school, viewing objects that interest children. Have them make field notes, including drawings and descriptions of the objects and specimens observed.
b. Put the hand-held microscopes in zip-lock bags and send them home overnight. Instruct the children to share the microscope and experiences with their parents and record their parents' reactions, which can be discussed in class the following day-along with interesting objects observed at home.
Related Books:
The World of Small by Michael Elsohm Ross, Yosemite Association, California, 1983. ISBN 0-939666-62-6
Magnification by Beth B. Norden and Lynette Ruschak, Lodestar Books, New York, 1993. ISBN 0-525-67417-9
Invisible Bugs and other Creepy Creatures the Live Within Us by Susan S. Lang, Sterling Publishing Company, New York, 1992. ISBN 0-8069-8208-X
Yikes! Your Body Up Close by Mike Janulewicz, Simon and Schuster Books for Young Readers, New York, 1997. ISBN 0-689-81520-4
Yuck! by Robert Snedden, Simon and Schuster Books for Young Readers, New York, 1996. ISBN 0-689-80676-0 3-D
Lungs and Micro Tongues by Shari Levine, Dr. Elaine Humphrey, and Leslie Johnstone, Sommerville House, New York, 1999. ISBN 1-58184-060-8
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