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Return to Trees Sprout Classroom Lessons Throughout the Year

Subjects Mathematics: Algebra Mathematics: Applied Math Mathematics: Arithmetic Mathematics: Measurement Mathematics: Statistics Science: Agriculture Science: Life Sciences: Botany Science: Physical Science: Environmental

Grades 3-5 6-8 9-12

Brief Description Complete the chart that shows locations and sizes of some of the biggest trees in the United States. Objectives Students will follow directions. work with partners or in small groups. measure accurately. accurately calculate data about a tree. Keywords Calculate, data, tree, measure, circumference, transpiration, calculator, height, Arbor Day, spring Materials Needed ruler stick or dowel, about 4 feet in length 8 small sticks (ice pop sticks will work well) per team/group roll of string square centimeter sheet plastic bag (optional) Lesson Plan In this lesson, students work in pairs or small groups to gather data about a tree. Each group might gather data about a different tree; all groups might collect data about the same tree; or two teams might gather data about each tree and compare their results. Measuring the Height of a Tree Explain to students that they can measure the height of a tree in the following ways: Stand at the base of the tree, and hold a ruler straight out in front of you in a vertical position. Close one eye and back away from the tree until you reach the point at which the ruler and the tree appear to be the same size. Stop and have a partner measure the distance between the tree and the ruler. That is the approximate height of the tree. One of the simplest ways to measure a tree's height requires a sunny day. Pound a stick or dowel into the ground. Measure the length of the stick above the ground, then measure its shadow. (For example, the stick might be 3 feet tall; its shadow might be 2 feet long.) Now you know that a 3-foot stick casts a 2-foot shadow. Measure the shadow cast by the tree. If the tree's shadow is 10 feet long, you can use a little algebra to figure out the height of the tree: If 2/3 = 10/x, then 2x =10 X 3 or 2x = 30, so x = 15; the tree is approximately 15 feet high. Students in the upper elementary grades and above can figure out the height of the tree by making a clinometer and using it to calculate the tree's height. For additional tree-measuring methods, see Following Fall: Measuring Tree Height or How to Measure a Big Tree. Measuring the Tree's Canopy (Leaf Cover) Provide students with 8 small sticks (ice pop sticks or small dowels work well), and explain that they should visualize the tree's leaf cover as a clock. Have students place sticks in the ground at the edge of the leaf cover at 12:00, 6:00, 3:00, and 9:00. Then have them place sticks halfway between each of those four sticks. When all eight sticks are inserted into the ground, students use string to create a large circle around all the sticks, and then measure the length of the string. The length of the string is the circumference of the tree canopy. Estimating the Number of Leaves on the Tree Have students count as accurately as possible the number of leaves on a small twig from the tree. Then have them count the number of twigs on an average branch, and calculate the approximate number of leaves on a branch. Then have them count the number of branches on the tree, and multiply the number of leaves on a branch by the number of branches on the tree. (Students might use calculators to complete this activity.) Have each student in the group calculate the number of leaves on the tree; the group then uses the average of its members' counts as its official "leaf census" number. Older students should produce a more accurate count than younger students. Estimating the Age of the Tree The approximate age of some trees can be estimated by measuring the distance around the trunk of the tree at a point five feet off the ground. If the tree's girth at that point measures 24 inches, the tree is approximately 24 years old. This method is not accurate for all trees. Contact a local tree expert or your university's extension service for additional information. Calculating the Average Size of a Leaf Students select four leaves of varying sizes from a tree. They use the square centimeter sheet to approximate the size of each leaf. That can be done by tracing the leaf on the centimeter sheet and counting how many squares (square centimeters) the leaf covers. Alternatively, you might provide students with the square centimeter sheets photocopied onto transparencies. Have students place a transparency over the leaf, color in the blocks that cover the leaf, then count the blocks. Extension Activity: Determining a Tree's Transpiration Older students can figure the amount of transpiration (water released) by a tree. (A mature tree can transpire more than 200 gallons per day!) In one method of determining the amount of transpiration, students tie a plastic bag over a group of leaves and measure the amount of water. For another more detailed method, see Determining the amount of transpiration from a schoolyard tree. Assessment Students share how they arrived at each of their calculations. You might have students write in their journals explanations of the math processes they used. Lesson Plan Source Education World Submitted By Gary Hopkins National Standards LANGUAGE ARTS: English GRADES K - 12 NL-ENG.K-12.12 Applying Language Skills MATHEMATICS: Number and Operations GRADES 3 - 5 NM-NUM.3-5.3 Compute Fluently and Make Reasonable Estimates GRADES 6 - 8 NM-NUM.6-8.3 Compute Fluently and Make Reasonable Estimates GRADES 9 - 12 NM-NUM.9-12.3 Compute Fluently and Make Reasonable Estimates MATHEMATICS: Algebra GRADES 6 - 8 NM-ALG.6-8.3 Use Mathematical Models to Represent and Understand Quantitative Relationships GRADES 9 - 12 NM-ALG.9-12.3 Use Mathematical Models to Represent and Understand Quantitative Relationships MATHEMATICS: Measurement GRADES 3 - 5 NM-MEA.3-5.1 Understand Measurable Attributes of Objects and the Units, Systems, and Processes of Measurement NM-MEA.3-5.2 Apply Appropriate Techniques, Tools, and Formulas to Determine Measurements GRADES 6 - 8 NM-MEA.6-8.1 Understand Measurable Attributes of Objects and the Units, Systems, and Processes of Measurement NM-MEA.6-8.2 Apply Appropriate Techniques, Tools, and Formulas to Determine Measurements GRADES 9 - 12 NM-MEA.9-12.1 Understand Measurable Attributes of Objects and the Units, Systems, and Processes of Measurement NM-MEA.9-12.2 Apply Appropriate Techniques, Tools, and Formulas to Determine Measurements MATHEMATICS: Problem Solving GRADES Pre-K - 12 NM-PROB.PK-12.2 Solve Problems That Arise in Mathematics and in Other Contexts NM-PROB.PK-12.3 Apply and Adapt a Variety of Appropriate Strategies to Solve Problems NM-PROB.PK-12.4 Monitor and Reflect on the Process of Mathematical Problem Solving MATHEMATICS: Communications GRADES Pre-K - 12 NM-COMM.PK-12.2 Communicate Their Mathematical Thinking Coherently and Clearly to Peers, Teachers, and Others MATHEMATICS: Connections GRADES Pre-K - 12 NM-CONN.PK-12.3 Recognize and Apply Mathematics in Contexts Outside of Mathematics SCIENCE GRADES K - 4 NS.K-4.3 Life Science NS.K-4.4 Earth and Space Science GRADES 5 - 8 NS.5-8.3 Life Science NS.5-8.4 Earth and Space Science GRADES 9 - 12 NS.9-12.3 Life Science NS.9-12.4 Earth and Space Science Find more great springtime lessons on Education World's Spring Lesson Plans page. Click to return to this week's Lesson Planning article, Trees Sprout Classroom Lessons Throughout the Year. Originally published 04/18/2003 Last updated 09/15/2008