Lesson Plan #:AELP-BOT0008

Bark Casts

An Educator's Reference Desk Lesson Plan

Submitted by: Darrell Spendlove, Lewiston Elementary School, Lewiston, Utah
Endorsed by: These lesson plans are the result of the work of the teachers who have attended the Columbia Education Center's Summer Workshop. CEC is a consortium of teacher from 14 western states dedicated to improving the quality of education in the rural, western, United States, and particularly the quality of math and science Education. CEC uses Big Sky Telegraph as the hub of their telecommunications network that allows the participating teachers to stay in contact with their trainers and peers that they have met at the Workshops.

Date: May 1994

Grade Level(s): 2, 3, 4

Subject(s):

OVERVIEW: When students look at a tree they often see only the leaves. This activity will give them the opportunity to make careful observations of the bark as well as learn to use bark to classify and identify trees.

OBJECTIVE(s):

1. Make a plaster cast of tree bark.
2. Use plaster casts of tree bark to make a simple classification system.
3. Use plaster casts of tree bark to identify individual trees.

MATERIALS:

Modeling clay, plaster-of-paris, pieces of poster board, pins, an area with a variety of trees.

ACTIVITIES AND PROCEDURES:

(Note, this activity can be done by individual students, or as groups of two, three, or four.)

1. Cast Making; Prepare by flattening out a stick of modeling clay so that it forms a rectangle about half and inch thick. Press the flattened clay hard into the bark of a tree. (Make sure that students push on the back of the clay as hard as they can.) Carefully peal the clay off the bark and roll the sides into a long U shape. Use pieces of poster board pinned into the clay to close off the ends to form a bowl. Mix plaster-of-paris and pour into the bowl. Let it set. When hard remove clay.
2. Have students group the casts according to similarities and explain why they grouped them the way they did.
3. Have the students or groups exchange casts and see if they can locate the tree that the cast was made from.

TYING IT ALL TOGETHER:

Discuss with students the importance of making careful observations. You may want to have the students paint the casts to make them look like the bark. Be sure that they try to make there colors match the bark and not just paint it brown.