## Plotting Ordered Pairs 2

### Kristy RousseauBay District Schools

#### Description

This is -part 2- of an introductory lesson that exposes students to identifying and plotting positive ordered pairs in a coordinate system. Prerequisite knowledge: origin, x- and y-axes, and a basic understanding of how to plot ordered pairs.

#### Objectives

The student identifies and plots positive ordered pairs (whole numbers) in a rectangular coordinate system (graph).

#### Materials

-1/4- graph paper (If students have completed the lesson -Plotting Ordered Pairs--Part I,- they may continue this lesson on the bottom half of their papers.)
-Ruler and/or a straight edge
-Pencils

#### Preparations

The teacher needs to:
1. Review students' sentences from -Plotting Ordered Pairs-Part I- and look for common misunderstandings and/or patterns that need to be further addressed in this lesson.
2. Gather rulers and/or straight edges.
3. Prepare overhead transparency for modeling purposes.
4. Have additional graph paper on hand for -mistakes- that may occur during the design process.

#### Procedures

1. Pass back the students' work from -Plotting Ordered Pairs-Part I.-

2. Review how to plot positive ordered pairs by addressing common misunderstandings that appeared when students explained in the first lesson how to plot (2,8).

3. Have the students draw and label a horizontal line for the x-axis about three blocks up from the bottom of the page. (Model as necessary using the overhead graph.)

4. Have the students draw and label a vertical line for the y-axis about three blocks from the left margin.

5. Students should then label the origin (0,0) and number the x- and y-axes to about -20.-

In this lesson, students will draw a simple shape on their coordinate system and identify the ordered pairs (points) that must be connected to complete the shape.

6. Have the students LIGHTLY draw a simple shape in their coordinate system. The shape must be constructed of points that can be connected with straight lines (basic geometric shapes and designs formed from these shapes are applicable).

7. Students should then list the ordered pairs of their points in a T-chart on the back side of their paper with the x and y points labeled accordingly. Once all of the points are listed, have the students erase their designs.

8. When the students are finished, they should -swap- papers with a partner.

9. Using the ordered pairs listed in the T-chart, the partner should plot the points on the graph, connecting them to complete the design. When the design is finished, the partner should sign his or her name on the paper and ask the -designer- if his or her work is correct. Any discrepancies should be discussed in order to figure out where an error was made.

10. During steps #six through nine, the teacher should be monitoring the students' work and assisting where needed.

11. After the majority of students have completed their
partners' designs, the teacher should conduct a final review of the lesson. Common errors that were observed during the monitoring stage should be addressed with additional examples and information.

12. On the backside, bottom half of the paper the students should explain in two or three sentences how they can use the x- and y-axes to graph ordered pairs.

#### Assessments

1) Check students' T-charts of ordered pairs to see if they correctly IDENTIFIED the ordered pairs that were needed to create the points of their designs.

2) Check their partner's paper to see if they were able to PLOT the ordered pairs given in their partner's T-chart.

3) Listen as students discuss discrepancies in their design plans and the actual results of their plottings. Use this information to help assess how students are identifying and plotting ordered pairs.

4) Read the students' sentences to gather information on their ability to use the x- and y-axes to identify and plot ordered pairs in the coordinate system.
If there is not sufficient evidence that students have mastered identification and plotting of ordered pairs, then additional activities need to be planned for further instruction (see Extensions).

#### Extensions

Depending on a student's ability to identify and plot ordered pairs, additional lessons may be needed to help clarify -trouble- areas such as confusing the x- and y-axes when plotting ordered pairs.
Students who have a strong grasp on this concept may begin asking questions about the -bottom- and -left-hand side- of the graph. It may be appropriate to lead these students through a discovery lesson exploring the other three quadrants of the graph and the negative numbers that exist beyond -0- on the x- and y-axes.
There are a variety of graphing activities available on the market to strengthen students' graphing skills. Many of them create pictures when ordered pairs have been plotted correctly.

This is the second lesson in a two part series. For the first lesson, see Plotting Ordered Pairs-Part 1.