Water, Water Everywhere...

This is a good beginning of the year lesson to review fractions, decimals, geometry (the number of degrees in a circle and drawing a circle with a protractor), graphing, and metric measurement. This lesson is a good way for students to meet their peers while working cooperatively in a task-oriented group. The watermelon you will be using for the activity is also a good start-of-the-year treat. Be sure to get an extra watermelon or two to share at the end of the activity.

A lesson plan for grade 6 Mathematics

By Jayne Brown

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Related topics

• Learn more about mathematics.

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Learning outcomes

Students will:

• review fractions, decimals, geometry (the measurement of a circle and use of the protractor), graphing, and metric measurement.
• learn the importance of water in the anatomy of organisms.
• learn the importance of working cooperatively to complete a task.
• organize and share data.
• collect and record data.
• use instruments to measure and record data.

Teacher planning

Time required for lesson

2 Days

Materials/resources

• Watermelon already sectioned into eight sections approximately the same sizes (Give one section to each group until all eight pieces have been used)
• newspaper for each group
• metal teaspoon for scooping for each group
• eight-ounce plastic cup for each group
• paper towels for each group
• flat surface work area large enough for three to four students to work with a section of watermelon
• small plastic trash bag for each group
• three pieces of plastic wrap for each group
• one balance and set of weights for each group
• calculator for each student
• worksheet 1 to collect the data for each student (see attachment)
• worksheet 2 for calculations (see attachment)
• protractor for each student
• a set of colored pencils for each student
• pencil for each student
• regular sheet of white, unlined paper for each student
• eight baskets or containers for storing needed materials
• student journals

In addition, the following must be done:

• The teacher will cut (prior to class) a watermelon into eight pieces of watermelon, approximately the same size.
• The teacher will have the students divided into groups of three or four students.
• Tables for each group will be prepared before class with covered newspaper.
• Balances with weights will be stationed at each group’s table.
• All other materials will be placed in a basket to be picked up by the Materials Handler in each group and will have one of each of the following:
  
  • plastic trash bag
  • metal spoon
  • paper towels
  • one calculator for each student
  • one box of colored pencils for each student
  • one protractor per student
  • one pencil per student
  • one worksheet #1 per student
  • one worksheet #2 per student
  • one piece of white drawing paper per student

(Once materials are picked up, the teacher will hand to each group three pieces of plastic wrap.)

Technology resources

Overhead projector

Overhead calculator (optional)

Pre-activities

Students will need to know the following:

• How to use a protractor
• How to measure a circle with the protractor
• A basic understanding of decimals, fractions, percents and use of a calculator
• Basic anatomy and systems of the human body
• Percentage of water in the human body
• What an organism is
• How to use a balance to measure mass
• How to make a prediction

These are teacher generated questions to be used with the class as an introduction:

• What does the word anatomy mean?
• What is a way you can display data?
• What is data?
• What is mass?
• What metric units do you use to measure mass?
• Name some systems in your body.
• How is each system important to you body function?
• What percent of your body is made of water?
• What substances are important to body functions?
• Is water important to your body?
• How is water important to your body?
• Is water found in plants?
• Where would water be found in plants?
• About what percentage of water would be found in a watermelon?
• Do you think it would be the same as in the human body?

Activities

Preparation

1. Prior to class, the teacher will cut a watermelon into eight pieces, approximately the same size.
2. Teacher will also have the students divided into groups of three or four students.
3. Tables for each group will be prepared before class with covered newspaper.
4. Balances with weights will be stationed at each group’s table.
5. All other materials will be placed in a basket to be picked up by the Materials Handler in each group and will have one of each of the following:
   
   • plastic trash bag
   • metal spoon
   • paper towels

   Each group will also have in the basket the following:

   • one calculator for each student
   • one box of colored pencils for each student
   • one protractor per student
   • one pencil per student
   • one worksheet per student
   • one piece of write drawing paper per student

Activity 1

1. Once materials are picked up, the teacher will give each group three pieces of plastic and one piece of watermelon on the plastic.
2. Using the scales, the group will find the mass of their piece of watermelon. This mass will be recorded in the proper place on their worksheet.
3. Students will find the mass of the plastic cup. This information will also be recorded in the proper place on their worksheet.
4. Students will seperate all the seeds from the pulp of the watermelon and place them on one piece of plastic wrap.
5. Then, using the balance, they will get the mass of the seeds on the plastic wrap and record them on the worksheet.
6. Students, using their spoon, will scoop out the melon pulp and place on one piece of the plastic wrap.
7. Using the the plastic cup and their hands to squeeze, the students will squeeze the water out of the pulp by holding the pulp over the plastic cup.
8. Students will find the mass of the water in the cup using the balance. They will write this mass on the proper place on the worksheet.
9. Then, they will subtract the amount of the plastic cup from this total amount and place this number on their worksheet.
10. Students will get the the mass of the pulp on the one piece of plastic wrap. This amount will be written on the worksheet in the proper place.
11. Students will place the rind on the plastic wrap and calculate the mass. They will record the mass on the worksheet in the proper place.
12. Each group will then clean up their watermelon, newspaper, and any scraps from the activity and place all of the waste in the plastic bag.

Activity 2

1. After area is cleaned, each student will get his/her pencil, set of colored pencils, worksheet 1, worksheet 2, unlined paper, calculator, and protractor and return to their seat.
2. This will start the second part of the activity which is calculating the data and graphing the results.
3. Students will interpret the data collected and place on worksheet 2 in the proper places.
4. The students will write the amounts as fractions on worksheet 2.
5. Using the calculator, the students will change the fractions to decimals.
6. Next, the students will change the decimals to percents.
7. Using the decimals, the students will multiply the decimal times 360 which is the number of degrees in a circle.
8. Now students are ready to make a circle graph with the information on sheet 2.
9. Place the protractor on the piece of paper. The teacher may do this on the overhead as the students work on their papers.
10. Mark the center of the protractor, (the belly button), and the line indicating the starting point of the protractor.
11. Using the protractor make a circle.
12. Mark off the first number of degrees and mark on the circle.
13. Pick up the protractor and make a straight line to the center of the circle. You now have a new starting line.
14. Continue placing the number of degrees on the circle.

Follow-Up

1. When students are finished, have them label, come up with a title, and color each section with a different color.
2. Question students orally about their findings.
3. Have students write an entry in their writing journal - “How does the watermelon compare to the human body?”

Assessment

• Worksheet #1-Check student data collected
• Worksheet #2-Check student calculations
• Circle Graph-Check student interpretation on data collected
• Questioning students orally about results of the lab
• Written response in the Student Writing Journal

Supplemental information

Attachments:

• Worksheet #1
• Worksheet #2

Related websites

N/A

Comments

This is a great activity for the beginning of the year. Later, the watermelon seeds can be planted and the “lab” watermelon parts can be fed to the wild animals. Then, you could teach about recycling and the environment.