Learning About and Using the Compass Rose

Transcription

1 Learning About and Using the Compass Rose Lesson: The 360 Degree Compass Rose and its Use Grade Level: 6 th Grade General Math Lesson Overview: This lesson will be used after completing lesson 3-6 (Pre-Transition Mathematics) on Angle Measure and Addition in order to show a real life use of a 360 protractor/compass rose. In this lesson the students will learn about and practice using a 360-degree protractor. This is important in that a good understanding of these angles makes navigation much easier. Finally students will apply their skills using the compass rose on a navigation chart to draw a line showing the intended course from one location to another. Sources Consulted: During the institute I realized the importance of truly understanding the compass rose in order to navigate using nautical charts. Sarah and I also discussed the fact that 6 th graders need a lot of practice this. Beyond class lectures, field investigations (especially activities 1 and 2) and consultations with classmates (Sarah Slade), I used the following sources when planning this lesson: Books: Bill Brogdon, Boat Navigation of the Rest of Us: Finding Your Way by Eye and Electronics (International Marine 2001) p , Web Sites: (A great site! Covers compass introduction, how to read a compass, units, and general uses of the compass. Also includes map skills, scales, lat/long triangulation, etc.) ( Gives a quick review of map basics, shows how to take a compass bearing from a map, talks about the two kinds of north, etc.) (Gives great boating information in the language kids can understand. Answers such questions as Why are there 360 degrees on the compass? and What is a knot? It gives a short history of navigation as well as how to calculate distance as well as many, many other topics. A great resource for kids!)

2 Materials Needed: 360 degree protractor (class set) Navigation charts (6 one per group of 4/5 students any navigation chart can be used) Pencil and eraser (1 per student) Computer Paper (1 sheet/student) Ruler (1 / student) Meter Sticks (1 / group) Drawing Compass (1/ student) Measuring Tape (at least 8 feet) Degree Cards (1 set) Rolling Ruler (to share) Computers (one per child) LOGO computer program Vocabulary: True North Also known as geographic north. This is the geographic north pole where all longitude lines meet. Magnetic North The direction of the earth s magnetic pole, to which the north-seeking pole of a magnetic compass needle points. This does not correspond to the geographic north. Compass Rose A circle marked in degrees from 0 to 360 and printed on maps and charts for use in navigation. The compass rose shows both true north and magnetic north. Navigation or Nautical Chart A representation of a maritime area and the adjacent coastal regions or shorelines. It shows water depths, heights of land, natural features, navigational hazards, locations of natural and man-made aides to navigation, etc. Rolling Ruler A ruler made for drawing/finding parallel lines Focus Question (Introducing the Lesson): While standing in the middle of the classroom, ask the students How can I get from where I am now standing to Johnny? Respond exactly to how they answer. If they say, turn and walk to him the response would be, how far do I turn?. Follow this short activity with a discussion of the importance of knowing where you are and what direction you want to go when navigating within the classroom or on a body of water! Learning Objectives: Students will construct a 360 degree compass rose Using a compass rose, students will determine a variety of bearings Students will use the LOGO program to set a number of bearings Students will distinguish between true north and magnetic north Students will use a navigation chart to draw a course line from one point to another.

3 Content Standards State of Illinois: Geometry 9.C.3b Develop and solve problems using geometric relationships and models with and without the use of technology. Measurement 7.B.3 Select and apply a variety of instruments (rulers, protractors) to the degree of accuracy required. Number Sense - 6.C.3a Select computational procedures and solve real world problems using whole numbers, fractions, decimals. Classroom Activities: Begin the lesson with the focus/introduction above. (5 minutes) Constructing a Compass Rose (10 minutes): Each student will construct a compass rose on a sheet of white computer paper. Distribute paper to each student. Using a drawing compass each student will construct a large circle in the center of their paper. Where would north, south, east, and west be on this circle? Mark these on your circle. Explain that when using a compass rose, one always goes clockwise from north in measuring degrees. How many degrees are there between north and east? Is this the same as between east and south? South and west? West and north? If it is 90 degrees between north and east how many degrees is it from north to south? Therefore, what would the corresponding degrees be for each of the directions? Once students have north (0 degrees) east (90 degrees) south (180 degrees) and west (270 degrees) ask to fill in other degree measures. They may work in small groups to complete this task. If a group is struggling, have them make a mark half-way between each pair of directions. Ask them what is half-way between 0 and 90 (northeast). Ask, How can you use this to figure out what degrees correspond to southeast, southwest and northwest? Have students complete the compass rose in as much detail as they can. This will allow the more advanced student to work towards smaller degrees of accuracy but at the same time allow the less advanced student to also complete the activity in the given amount of time. While students are working in pairs or small groups, have one group create a large compass rose in the center of the classroom (on the floor, using chalk) This will be used in the next activity.

4 Classroom Compass Rose (10 minutes): Once students have completed their own compass rose, they should have a much idea of degrees that make up compass rose. This next activity will take their knowledge to the next level. Have all but 2 students sit in a circle around the large compass rose that is drawn on the classroom floor. Be sure one student is positioned at each of the main directions (north, northeast, east, southeast, south, southwest, west, and northwest.) All other students can fill in in between. The circle of students may have to be a distance from the actual compass rose. If this is the case, be sure to have a long enough measuring tape on hand. The two students not in the circle will be the boat and the navigator. Have the boat stand at the very center of the compass rose. Have the navigator select a Degree Card from the deck. The boat will then turn the number of degrees given. The navigator will then confirm (or help out the boat if the direction is incorrect) the bearing and have the boat walk directly, following that bearing, to the closest person they come to in the circle. The boat will then exchange places with that person and the new person will become the navigator and the previous navigator will then become the boat. Continue this as long as time permits. Turtle LOGO: (10 minutes) When the above activity is complete, have students take a laptop from the COWS and return to their seats. They should all open up LOGO. (My students have had some basic instruction with this program.) When the turtle is HOME it is always pointing north. All turns used today will be right turns (RT). On the board, write: 45 degrees, 160 degrees, 200 degrees, 25 degrees, and 310 degrees. For each specified degree, they should move the turtle forward 200 units. After each move they need to type HOME before beginning a new turn. When they are finished, they will have a star-like pattern. Each student will print out their pattern. These patterns are just lines.they are not labeled with degrees at this point. Erase the board and rewrite the same degree measures in a different order. Using their developing knowledge of the compass rose, they should label each line with the correct number of degrees. NOTE: they may not use the drawing of the compass rose they previously made while doing this activity! This printout will be turned in at the end of class, along with their hand-drawn compass rose. Computers will be put away. Navigation Charts (20 minutes) Each group (3-5 students) will be given a navigation chart. Ask students to find the compass rose(s) on these charts. If a student does not raise their hand to ask about why there are two different ones (a crooked on inside a straight one. Or whatever their language might be!) guide them to this discovery. At this time review (or teach depending on their background knowledge) the difference between true north and magnetic north. If a magnetic compass is available through the science department see if this difference is noticeable. Discuss : Why a navigator of a boat needs to know the

5 difference between true north and magnetic north? What part of the compass rose should a navigator use? What would happen if they used the wrong one? Have each group choose a location on the map. (You may have them all choose the same location, or you could have each group select their own.) Using a pencil, lightly mark a you are here X on that location. Select a location (again, one for the entire class or let each group choose their own) to where you want to go mark this also with a light X. Use a meter stick or ruler (depending on how far apart these are on the map) to draw a light line connecting these points. They may have to extend their lines in order to complete this activity. Discuss how they will determine what their bearing will be in order to get from the first to the second location. Introduce the rolling ruler at this point. If there is only one rolling ruler it may be circulated among the different groups. This will also ensure that the teacher is there to ensure that this tool is used correctly. On separate sheet of paper, each group should write down their beginning and end locations along with the bearing that they determined. All of their names should be on this one paper. They will turn in their chart (tell them NOT to erase any lines as these charts will be used in another lesson later on) along with their paper at the end of class. If time permits, the groups may select a second leg of the journey and determine the bearing for this. Conclusion (5 minutes): Review the day s lesson. Go over each of the vocabulary words. Have students add these words to their vocabulary journals. Ask: What did you like best about today s lesson? (write their responses on the board) Ask What did you learn today that you didn t know before? Write this on the board also. Have one student act as a scribe and make a class copy to post on the bulletin board for future reference. Assessments: 1) Student s work and interactions will be informally assessed throughout the class period, with notes made as to which students seem to be having difficulty. A point should be made to spend some 1:1 time at some point during the lesson with these students, or match these students up with a student who seems to have a good grasp of the material. Students who had a difficult time during the classroom compass rose activity can be invited for lunch with the teacher where they can come to the classroom to eat and then have more practice with this activity. 2) Collect the compass rose each student made. (make a note of the students who made the large floor model so that credit is also given to them!) Look for degrees of accuracy and correctness of each compass rose.

6 3) Collect the LOGO printout of the bearings and their degrees from each student. This will show how well the students understand the 360 compass rose by matching the list of degrees with their printout. 4) Collect the navigation chart and attached paper from each student group. The bearing(s) they determined will be check for accuracy. 5) Read over the lists of what the students liked best about the assignment and what they learned from today s lesson.

7 DEGREE CARDS Copy, laminate and cut out the cards below. These will be used in the Classroom Compass Rose Activity. You may add more cards to the deck if you would like. 0 degrees 45 degrees 90 degrees 135 degrees 180 degrees 225 degrees 270 degrees 315 degrees