Primary Type: Lesson Plan
Status: Published
This is a resource from CPALMS (www.cpalms.org) where all educators go for bright ideas!
Resource ID#: 56969
The Mystery of Crop Circles... on a coordinate plane
In this lesson, students will use their knowledge of plotting points on quadrant I of the coordinate plane to figure out other coordinate pairs within
quadrants II, III, and IV. Students are challenged to match description cards to the matching "map" (four-coordinate grid). As an extension or
next lesson, students will draw their own polygons on the four-coordinate grid and provide the coordinates for each.
Subject(s): Mathematics
Grade Level(s): 6
Intended Audience: Educators
Suggested Technology: Internet Connection, LCD
Projector, Speakers/Headphones, Computer Media
Player
Instructional Time: 1 Hour(s)
Freely Available: Yes
Keywords: geometry, coordinate plane, grid, polygon, plot, ordered pair
Resource Collection: CPALMS Lesson Plan Development Initiative
LESSON CONTENT
Lesson Plan Template: Confirmatory or Structured Inquiry
Learning Objectives: What will students know and be able to do as a result of this lesson?
Students will be able to:
understand the structure of the coordinate plane.
plot ordered pairs in all four quadrants of the coordinate plane.
use given coordinates to locate polygons on the coordinate plane.
draw a polygon and give its coordinates on any quadrant of the coordinate plane.
Prior Knowledge: What prior knowledge should students have for this lesson?
Prior to this lesson, students should be able to:
Draw, locate, and name coordinates of polygons on quadrant I of the coordinate plane.
Identify polygons, including rectangle, square, trapezoid, and hexagon.
Find the area of simple shapes (square, rectangle).
Be familiar with the difference between units and square units.
Explain a number line in terms of positive and negative direction.
Guiding Questions: What are the guiding questions for this lesson?
Guiding questions the teacher may use include:
What do you already know that will help you if you are stuck?
What does this remind you of?
How do I know if this is on the x-axis or the y-axis?
Why are you going left (right, up, down)?
Can you explain your partner's thinking?
Introduction: How will the teacher introduce the lesson to the students?
page 1 of 3 1. To introduce this lesson, the teacher should tell students she has been thinking about a very mysterious thing lately: crop circles. Engage students in a short
discussion on crop circles.
2. The teacher should show the following video from National Geographic on the Mystery of Crop Circles (4min, 25sec) to further engage students.
3. After showing the video, the teacher should tell the students that scientists who investigate these crop circles use aerial photography to measure the sizes of the
figures and what shapes are used. To help them do this, they overlay the pictures onto coordinate grids to keep track of the figures, and that she has created some
maps that represent fields and crop polygons! The teacher should post a large four-coordinate plane on the board for all students to see.
4. The teacher should ask students what they notice about the map (it is a grid called a coordinate plane). The teacher should ask students if they see a number line
anywhere on the map (the axes). The teacher should explain to students that when the number lines are intersected perpendicularly, they create the coordinate
plane. The intersection of these number lines is called the origin. (Students should know this is the point where the x and y axis cross, and is marked 0,0.)
5. The teacher should review with students how they would plot a coordinate pair on quadrant one of the coordinate grid (follow the number along the x-axis then the
y-axis). The teacher should also label this quadrant "quadrant I" on the large display coordinate grid.
6. The teacher should ask students how we would name a point (use (-2,4) for an example) located in this position on the coordinate plane (follow the x axis to -2 and
the y-axis to 4, plot the point). The teacher should label this quadrant "quadrant II" on the large coordinate plane.
7. The teacher should repeat step 6 with quadrant 3 and quadrant 4, giving an example of the coordinates and the name of the quadrant each time.
8. The teacher should tell students that she thinks they are ready to give this a try on their own with their own crop polygon maps!
9. The teacher should hand out a set of maps and description cards to each pair of students.
10. When students finish successfully, the teacher should tell students that they have an even tougher challenge and that this time the map is blank! Only the clues
exist. The teacher should challenge students to use the clues to create the map of crop polygons. The teacher should pass out a blank 4 quadrant grid and the clues
for polygons. (Answer key)
Investigate: What question(s) will students be investigating? What process will students follow to collect information that can be
used to answer the question(s)?
Students are investigating which description card goes with which crop polygon map. Students will be able to use process of elimination for some of the cards, but
must rely on locating the coordinates for most shapes. Also, there are descriptions of side length, area, and specific names of polygon students will be able to use to
identify which map matches each description card.
After finding the matching cards and maps, the students will draw polygons on a coordinate grid based on clues given.
Analyze: How will students organize and interpret the data collected during the investigation?
Students will need to talk with their partner while working to justify their thinking. Students can glue the description card onto the map they think it matches once they
have found their solution.
Closure: What will the teacher do to bring the lesson to a close? How will the students make sense of the investigation?
After students have had ample time to make the matches with the cards and maps, the teacher should bring the students together and have a whole group discussion
about their findings. Some discussion points and questions might include:
Do all of the partners agree?
What made it easy to figure out the matches?
What made it difficult to make some matches?
How might people get confused when plotting or locating coordinates on the 4 quadrants?
How is using a four quadrant coordinate grid like using only quadrant 1 as they have used before?
How could being able to locate points on the plane help students be able to draw their own crop polygon maps?
Summative Assessment
The teacher may use the same assessment given at the beginning of the lesson to find out what students have learned.
Another option is this assessment from www.illustrativemathematics.org, "6.G Polygons in the Coordinate Plane." However, this assessment includes finding the area
of polygons, which is not covered during this lesson. It would be a nice formative assessment for a future lesson on finding area, though.
Formative Assessment
The teacher can use the following formative assessment before the lesson to find out the students' understanding of plotting points on a coordinate plane.
Feedback to Students
During the lesson, the teacher should be sure to ask students questions to clarify their thinking. Such questions might include:
How do you know that is true?
Show me where you are talking about on the coordinate plane.
What is that called (referring to shapes' names)?
Which axis are you referring to?
ACCOMMODATIONS & RECOMMENDATIONS
Accommodations:
To accommodate students with special needs during this lesson, the teacher could conduct a small group of students working together one map and one description
card at a time. The teacher could also cut the number of maps and description cards to two instead of four.
For students who finish quickly, the teacher can challenge them to find the area of each of the crop polygons on the maps.
Students should be given the opportunity to draw their own crop polygon shapes and name the coordinates. This could be given as a homework challenge or be the
activity for the next day.
Extensions:
A possible extension of this lesson would be for students to create their own set of maps and description cards for each other to figure out.
page 2 of 3 The teacher could also provide an extension by giving students description cards and blank grids on which students would plot points and draw polygons. (or vice
versa; provide polygons on grids and have students create the description cards)
Suggested Technology: Internet Connection, LCD Projector, Speakers/Headphones, Computer Media Player
Special Materials Needed:
The teacher will need print outs of the maps and description cards for each pair of students.
The teacher will need to make sure the National Geographic video on the Mystery of Crop Circles works and can be presented to students.
Further Recommendations:
If the ability to show the National Geographic video does not exist, the teacher can show pictures or tell stories about crop circles to students instead.
Additional Information/Instructions
By Author/Submitter
Students who experience this lesson will engage in the math practice standard MAFS.K12.MP.5.1, use appropriate tools strategically, as they learn to use a coordinate plane.
The coordinate planes included in the lesson were found at www.mathbits.com and www.math-aids.com.
SOURCE AND ACCESS INFORMATION
Contributed by: Heather Williams
Name of Author/Source: Heather Williams
District/Organization of Contributor(s): Volusia
Is this Resource freely Available? Yes
Access Privileges: Public
License: CPALMS License - no distribution - non commercial
Related Standards
Name
MAFS.6.G.1.3:
Description
Draw polygons in the coordinate plane given coordinates for the vertices; use coordinates to find the length of a side
joining points with the same first coordinate or the same second coordinate. Apply these techniques in the context of
solving real-world and mathematical problems.
page 3 of 3