PREINSTRUCTIONAL:

Objectives:

• Students will estimate the life size height or length of a desert plant or animal using measurements given.
• The students will create pictures that compare their estimates with the true size of the plant or animal.
• Students will apply what they learned about measurement in a class discussion.

Materials:

• Butcher paper
• Chalkboard or large wall to cover
• Markers, crayons, pencils
• Yardsticks, rulers, and tape measures
• 3X5 index cards with the plant or animal name and size written on it.
• Glue
• Several objects, such as the cactuses that are used in the classroom.

PREPARATION:

1. Hang white butcher paper on a large wall or chalkboard.
2. Create index cards with the plant or animal name on them:
   Size Information:

   PLANTS	ANIMALS
   barrel cactus: 24 inches tall	coyote: 36 inches+12 inch tail
   creosote: 60 inches	jackrabbit: 19inches+4in.tail
   Indian paintbrush: 18 inches	kangaroo rat: 4 inches + 5in.tail
   prickly pear: 24 inches	Gila monster: 18 inches
   wildflowers: 12 inches	rattlesnake: 24 inches
   yucca: 36 inches	tarantula: 4 inches
   	vulture: 25 inches

   (Source: Deserts Published by Creative Teaching Press)

DURING INSTRUCTION

1. By table (3 to 4 students), the students will choose an index card with the plant or animal name printed on it.
2. The group will estimate the size of the object, and record it on the butcher paper using small x's, and a line connecting the x's.
3. The students will then use measuring tools to make a true-to-life representation at their tables.
4. The students will cut out and paste their life-size representations above or next to their estimations.
5. The class will review the plants and animals on the wall, discussing measurement and how it is different or the same as what the predictions were.
6. The students will be asked to estimate the sizes of objects that the teacher holds up, such as the cactuses that are in the classroom for experimentation.

POSTINSTRUCTIONAL

• Were the students close in their estimations? Were the students surprised by the real life sizes next to their estimations?
• Did the students draw the estimations and the real sizes, comparing them to each other?
• Were the students able to apply what they learned about measurement in the class discussion?

• If the students do not understand the different measurements, a chart may be made that depict the different rulers, and the marks on them. The teacher may also bring in several different types of measurement tools, such as a yardstick and tape measure.