Beacon Lesson Plan Library

A Penny for Your Thoughts (High School)

Elizabeth Russell


Students work cooperatively in small groups to form hypotheses. They will then form theories that can explain their hypotheses and will test these theories and evaluate the results.


The student knows that investigations are conducted to explore new phenomena, to check on previous results, to test how well a theory predicts, and to compare different theories.


-Water containers
-Paper towels
-Water Laboratory Data Sheets


1. Make copies of the “Water Laboratory Data Sheet” for each group.
2. Obtain pennies, droppers, container of water and some paper towels for clean-up.
3. Make sure students have a flat surface on which to work.


1. Assign the students into groups of two to three.

2. Distribute to each group one penny, one eye dropper, one container of water and paper towels.

3. Distribute to each group one copy of the “Water Laboratory Data Sheet”.

4. Read over the instructions with the students.

5. Explain to the students that each person in their group should give their idea of what the hypothesis would be.

6. Tell the students to write down each of the stated hypotheses and allow group discussion to review each of the proposed hypotheses.

7. Tell the students that after their group has chosen its hypothesis, they should discuss and arrive at a theory that explains their hypothesis.

8. Explain to the students that they should arrive at a consensus of the group as to the final hypothesis and theory for this problem and write it in on their data sheet.

9. Explain the different jobs to the groups:
Water dropperer—slowly drops water onto the penny one drop at a time
Data recorder---records the information onto the data sheet
Counter/go-fer---counts the drops at they hit the penny and is in charge
of getting the laboratory items as needed

10. Tell the students to decide who in their group will have each of the following jobs for their group: water dropperer, data recorder and counter/go-fer.

11. Tell your students to place a paper towel under their penny on a flat surface.

12. Explain to the students that they each must do the job they have chosen for their group. They cannot switch jobs in the middle of the lab because that could be a variable that changes the lab’s outcome.

13. Ask if there are any questions about what each person is suppose to do.

14. Tell the students to begin.


Use the students’ answers on the “Water Laboratory Data Sheet6” (see associated files) to assess students’ knowledge of the standards.


You could have the students use other water solutions such as salt water or lemonade. They could then predict if the added materials in the water would change the outcome of the experiment and test this theory.
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