Measuring Pumpkins and Our World
- Grades: PreK–K
- Unit Plan:
- Estimate the circumference of a pumpkin.
- Compare their estimate to those of their classmates.
- Measure familiar objects in the school.
- Record measurements.
- One pumpkin
- Yarn, scissors, paper, and a stapler to tag each child’s length of yarn
- Chart with three columns labeled "Too Short," "Just Right," and "Too Long"
- Copies of The Official Measure-the-School Book (PDF) from The New Kindergarten: Teaching Reading, Writing & More
- Clipboards (optional)
- Measuring tools (this will depend on what you decide to use with your class)
Set Up and Prepare
- Prepare the chart mentioned in materials.
- Make enough copies of The Official Measure-the-School Book (PDF) printable for each team. Customize the books to represent the objects you want measured.
Measuring, estimating, and comparing are important math skills. Students may use standard or nonstandard measurement for these activities. Be sure to pay attention to the ways they approach these activities and how they solve problems. Learning to think about numbers and measurements and how they get this mathematical data is as important as doing the activities "correctly."
Day 1 – Measuring Circumference
Step 1: Bring out a pumpkin and show it to the students. Start a short discussion about the size of the pumpkin, asking questions like "If you had to tell your Mom how big this pumpkin is, what would you say?" and "What’s bigger than this pumpkin? What’s smaller?"
Step 2: Explain that they will have the chance to estimate how big the pumpkin is around its middle by cutting a piece of yarn as long as the pumpkin is round. Draw a line around the part of the pumpkin that you’ll be measuring. Let the students know that this is called the circumference of the pumpkin. Give them other examples of things that have a circumference, like balls or oranges.
Step 3: Give students time to cut a piece of yarn to represent their estimation. Allow them to examine and touch the pumpkin in order to figure out how long they think the yarn should be. Staple a tag with their name on it to their piece of yarn.
Step 4: Call students back together in a large group. Show them the chart you’ve made. In front of the students, wrap a piece of ribbon around the circumference of the pumpkin and cut it. Tape this ribbon in the "Just Right" category on the chart. Then have the students come up and compare their yarn to the ribbon and the pumpkin and tape their piece of yarn in the correct area of the chart.
Step 5: Discuss whether or not they were surprised by the actual measurement. Who was the closest to the correct length? How did that student guess so closely?
Day 2 – Measuring the School
Step 1: Discuss ways of measuring with students. Maybe this includes introducing units of measurement like inches or feet, or maybe you use nonstandard units, such as piece of yarn you've cut. Talk about how to hold the measurement tool in a straight line and model recording the measurement of a few familiar objects.
Step 2: Break the students up into teams (two per team works well) and go over the instructions. Each team will get a clipboard and a copy of "The Official Measure-the-School Book" handout. The teams will together use a measuring tool (a yardstick with inches works well) to measure familiar objects in the school. This can be a fun traveling activity around the school, or you can design it to take place in the classroom. Extend this activity by asking students to estimate before measuring.
Step 3: Gather teams back to share their work and discuss the process as a class. Compare the measurements from different teams. Ask: Are the measurement the same or different? Why might this be? Did they have any problems getting measurements? What were the problems they had that they couldn't solve? Ask other students to help find a solution if the team cannot. Congratulate them for their great work collecting important math data.
Supporting All Learners
Be ready to assist students who may struggle with using the measuring tools or writing the data. Encourage all progress and teamwork.
Baking is an everyday task that introduces young children to another need for measurement. I like to make pumpkin pie with the class, allowing the students to participate as much as possible. (Do this early in the morning so you’ll have time to make, cook, cool, and eat the pies before they go home.) I suggest this simple recipe:
- Solid Pack pumpkin (The amount will vary on the size of your class.)
- 2 cans of evaporated milk
- 4 eggs, slightly beaten
- 1 1/2 cups sugar
- 2 tablespoons flour
- 1 teaspoon salt
- 1 teaspoon ground cinnamon
- 1/2 teaspoon ground ginger
- 1/2 teaspoon nutmeg
- 1/4 teaspoon cloves
- individual graham cracker pie shells
Preheat oven to 450 degrees. Mix ingredients. Divide into the individual graham cracker pie shells. Bake approximately 20 minutes. Reduce temperature to 350 degrees and bake 40 minutes longer. Cool completely on rack. (If you are unable to do the baking at school, I suggest bringing baked pies to share with them after letting the students make the filling in class.)
Students can make booklets for home and measure objects in their home. These could then be shared with the class.
Students estimate the circumference of a pumpkin and compare their estimations to the actual circumference. Students measure familiar objects in the school and record their measurements.
- Were the students engaged?
- What kind of activities caused the students problems and what can I teach to help them overcome these problems in the future?
- How might I do this lesson differently next time?
- What kind of observations about measurement are the students making?
- Are the students’ estimations close to the actual circumference?
- Are students making good comparisons?
- Are the students able to measure using the measuring tool?
- Are the students able to record accurately? If not, what are they recording?