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 3foot stick casts a 2foot 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
an inclinometer and using it to calculate the tree's height.
 For additional treemeasuring methods,
see Following
Fall: Measuring Tree Height, How to Measure a Big Tree, or Measuring Guide.
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 NLENG.K12.12
Applying Language Skills
MATHEMATICS: Number and Operations GRADES 3  5 NMNUM.35.3
Compute Fluently and Make Reasonable Estimates GRADES 6  8 NMNUM.68.3
Compute Fluently and Make Reasonable Estimates GRADES 9  12 NMNUM.912.3
Compute Fluently and Make Reasonable Estimates
MATHEMATICS: Algebra GRADES 6  8 NMALG.68.3
Use Mathematical Models to Represent and Understand Quantitative
Relationships GRADES 9  12 NMALG.912.3
Use Mathematical Models to Represent and Understand Quantitative
Relationships
MATHEMATICS: Measurement GRADES 3  5 NMMEA.35.1
Understand Measurable Attributes of Objects and the Units,
Systems, and Processes of Measurement NMMEA.35.2
Apply Appropriate Techniques, Tools, and Formulas to Determine
Measurements GRADES 6  8 NMMEA.68.1
Understand Measurable Attributes of Objects and the Units,
Systems, and Processes of Measurement NMMEA.68.2
Apply Appropriate Techniques, Tools, and Formulas to Determine
Measurements GRADES 9  12 NMMEA.912.1
Understand Measurable Attributes of Objects and the Units,
Systems, and Processes of Measurement NMMEA.912.2
Apply Appropriate Techniques, Tools, and Formulas to Determine
Measurements
MATHEMATICS: Problem Solving GRADES PreK  12
NMPROB.PK12.2
Solve Problems That Arise in Mathematics and in Other Contexts
NMPROB.PK12.3
Apply and Adapt a Variety of Appropriate Strategies to Solve
Problems NMPROB.PK12.4
Monitor and Reflect on the Process of Mathematical Problem
Solving
MATHEMATICS: Communications GRADES PreK  12 NMCOMM.PK12.2
Communicate Their Mathematical Thinking Coherently and Clearly
to Peers, Teachers, and Others
MATHEMATICS: Connections GRADES PreK  12 NMCONN.PK12.3
Recognize and Apply Mathematics in Contexts Outside of Mathematics
SCIENCE GRADES K  4 NS.K4.3
Life Science NS.K4.4
Earth and Space Science GRADES 5  8 NS.58.3
Life Science NS.58.4
Earth and Space Science GRADES 9  12 NS.912.3
Life Science NS.912.4
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 03/20/2010
