Beacon Lesson Plan Library

Barge Building…What Floats Your Boat?

Glenn Rutland
Santa Rosa District Schools


Using aluminum foil, pennies, and water, students build a barge that will float while holding the largest number of pennies. Students will learn problem solving, estimation, weight and balance, and the causes and effects of water displacement.


The student uses problem-solving strategies to determine the operation(s) needed to solve one- and two-step problems involving addition, subtraction, multiplication, and division of whole numbers, and addition, subtraction, and multiplication of decimals and fractions.

The student chooses, describes, and explains estimation strategies used to determine the reasonableness of solutions to real-world problems.

The student solves real-world problems involving measurement of the following:length (for example, eighth-inch, kilometer, mile); weight or mass (for example, milligram, ton); temperature (comparing temperature changes within the same scale using either a Fahrenheit or Celcius thermometer); and angles (acute, obtuse, straight).


-Aluminum foil
-Tub with colored water (number of tubs used will depend on number of students)
-Pennies (have at least 100 available for use)
-Comparison chart (download file)


2. Cut out 8 x 8 pieces of aluminum foil (at least 2 for each student)
3. Have tubs/colored water set up on sturdy table
4. Make copies of -Comparison Sheet- for each student


Day One:
1. Begin this lesson with information about the displacement of water. Discuss how the size and weight of the object in the water determines the amount of water displaced.

2. Reinforce this information with Bill Nye's video on buoyancy. This will help students understand weight and mass and its effect on the buoyancy of an object. Students will begin developing problem-solving strategies as they begin the design of their barge.

Vocabulary : displacement, buoyancy, surface tension, estimate.

Day Two:
3. You will want each student to have a sheet of aluminum foil (8”x 8”). I have found that it is better that I furnish the foil, that way they all have the same weight foil. Have extra foil available for the students who want to experience different designs or for the students that may have “accidents” when handling their foil.

4. Have students shape their foil into a design that they think will support the most pennies without the barge taking on water.

5. Students need to now estimate how many pennies they think will fit on their barge when it is floating in the water. Write this estimation on the Comparison Chart.

6. After all students have written their estimation and experienced loading their barge with pennies, they then need to write on their -Comparison Chart- the actual number of pennies that they were able to load on their barge.

7. Using these two recorded figures from the -Comparison Sheet,- allow the students time to determine the difference between the amounts. Students can use this information to compare with other student’s numbers in the classroom.

8. Students can now get a class average using all of the information that they have compiled.

9. Students may also graph information gained from this exercise. This graph could be displayed on the classroom wall for students to be able to compare their results with others.


Students demonstrate their ability to solve problems through reasoning and generate new ideas by the successful completion of the Barge Building activity. This is assessed through teacher observation and student completion of the Comparison Chart.


1. Students can work with averages by building multiple barges of different designs and averaging the number of pennies loaded to each individual barge.
2. Students can be divided into groups to determine if -team- building builds a better barge.

Web Links

Web supplement for 'Barge Building…What Floats Your Boat?'

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