Learning Lesson: What-a-cycle

Overview

At its basic, water moves from the earth's surface to the atmosphere and then returns to the surface. However, the actual path water may take in its cycle is far more complicated. The students will discover more of these cycles by acting as water molecules and travel through parts of the overall water cycle.

TOTAL TIME	20 minutes
SUPPLIES	A die for each student or each pair of students (or some device where a random number from 1 through 6 can be generated).
PRINTED/AV MATERIAL	Station cards (8 mb) for each station in the water cycle (print two-sided). Large labels (13 mb) for each station. Water cycle worksheet (for each student).
TEACHER PREPARATION	Before the exercise, print the front and back sides of each station card on its own sheet. Cut out each of the six cards for each station. Around the classroom, select locations to represent different stations in the water cycle. Place the large labels and numbered cards (1-6), picture side up, at each station.
SAFETY FOCUS	Flash Flood Safety

Procedure

1. Distribute a die to each student or pair of students (or distribute dice at each station). Distribute a worksheet for each student.
2. Pre-station the students to different portions of the water cycle by:
   • Placing one-half of students at the 'Oceans' station.
   • Evenly spreading the remaining students across the other stations except for the 'plants' station.
3. Have each student circle their starting location on their worksheet.
4. Each student is to roll their die.
5. Based upon the number rolled, the student turns that number card over to determine their progress in the water cycle.
6. If told to move draw, an arrow on their worksheet from their current position to the station indicated by the card. Label that arrowhead with a number one (1). The student then moves to their new location.
7. If told to stay at their current position, have the students place a number one (1) inside their drawn circle.
8. Each student is to roll their die again.
9. If told to move, on their worksheet, draw an arrow from their current location to their new position. Label that arrowhead with a number one (2). The student then moves to their new location.
10. If told to stay at their current position, have the students write a number two (2) at their current location.
11. Repeat the "die roll and move" procedure up to a total of ten (10) times.

Discussion

Most students should have traveled to several stations and have completed some sort of a cycle. Some students may have traveled through most of the water cycle while others have moved very little. There also may be a student or two who remained in the ocean through all ten turns.

While this exercise is to be somewhat realistic, in actuality it is far more complicated to leave the ocean via evaporation due to the fact that nearly all of the earth's water is confined to the oceans. To truly represent the water cycle we would need approximately 100,000 people located at each station as seen in the table (right)(below).

Not only would there be over 97,000 people who represented the ocean, it would take close to 3,600 rolls of the die before just one person would move to the atmosphere station via evaporation.

This exercise also does not take into consideration human and animal interactions with the water cycle. The water humans and animals consume is stored and then eventually eliminated or it evaporates (via perspiration).