Field Trip Planner: Measuring Math

3. Measuring Math.

OBJECTIVE:

(1) An introduction to metrics or as a reinforcement to subjects already taught.

(2) Practical applications of math.

(3) Reinforce concepts of data accuracy.

TIME REQUIRED.

One hour depending on how much work was completed before coming to field site.

CONTENT MATTER:

The term "biometry" is used to describe a series of standard measurements used to describe a vegatated study site. Students will learn to gather biometry data by measuring tree height and circumference (see Resources http://bellnet.tamu.edu/res_grid/elementry/rsrcele.htm)).

ACTIVITIES:

(1)Determine pace count. Students will determine how many paces he/she must walk to cover 100 meters. Measure out a 100 meter pace course. A good location is along the mural wall. Students will walk the course and count their paces. Walk back to the start point, again counting paces. Compute the average of the two walks. The number is the students 100 meter pace count. Remind the students that each person will have a different pace count for 100 meters. When going uphill, normally it will take more paces to go 100 meters. Going down hill will take fewer paces. Test student understanding by having them determine the distance of a premeasured course by pacing off the distance.

(2) Measure Tree Height. Students may determine the height of an object by a indirect method. A clinometer or improvised Hypsometer-Clinometer and a Table of Tangents along with a measuring tape or accurate pace count may be used to determine the height of a object. Students measure a base line distance away from the object to be measured. The student then uses the Hypsometer-Clinometer to determine the angle to the top of the tree. Multiply the angle’s tangent by the base line distance and add the height of the eyes of the observer (1.5 meters). This gives you the height of the object. (Note: When your clinometer shows an angle of 45 degrees at the top of the object you are measuring, the distance from you to the object is the same as the height of the object.) The mural wall is a excellent place to set up measuring points. After the students have computed the height of the wall at various points, measurements may be taken using a 50 meter tape from the top to the bottom. Have students first estimate the height of the wall, then compute the height, then record the tape measured figure. Students should record this data in their field notes. Teachers will have plenty of data to have students compute team accuracy percentages and other basic math computations back in the classroom.

(3)Measure Tree Circumference. Students will measure the circumference using a flexible metric tape. To insure data accuracy, all measurements should be made at the same height. Measure the tree trunk at a height of 1.35 meters from the ground. There are several locations along the Old Tennessee Valley Trail, and Area C near the Old River Channel where student teams can take tree height and circumference measurements. Student teams can measure the same series of trees, and have good data for accuracy comparisons and other basic math problems back in the classroom.

(4) How Much Further? You can put a stop to this question by having students keep track of the distance they have traveled using their 100 meter pace count. Have teams assign duties like recorder, navigator and two people to count the pace. Students will find that if they do not have a method for keeping track of they distance covered, they will soon lose count. Have students tie a knot in a string or put a small stone in their pocket every time they cover 100 meters. At the end of the hike, have the data recorded in field notes for comparison back in the classroom.

(5) Land Navigation. This is a good activity for students that have had some compass and map reading preparation at school before coming out to Miller Springs. The best place to run this activity is in the spillway area between the mural wall and the parking area. It does require significant station preparation. The station leader must "survey in" the navigation point and different lanes. A master list with the distance/azimuth between selected navigation points must be prepared. The Land Navigation Station may be set up either in a circle or in two parallel lines. Students are provided with a instruction sheet that tells each navigation team to move on a specific azimuth for a specified distance in meters. They should arrive at a specific marker, record the letter/number at that location and then navigate to the next location. Normally three to four stations will take at least the full hour. Teachers may add to the activity by having the students answer a question at each point. This activity lends itself to both a individual and group grade. If the activity is to be scored, the station leader needs to establish a way to check each navigation team at each station since missing the first point will result in missing the remaining points as well. If you are short on adult assistance, modify the exercise by directing the students to record the site that they are at and then move to a specific marker and continue with the navigation problem. Identify the navigation points with a letter sign or some type of positive identification.