Lesson Notes By Weeks and Term v4 - JHS 1

Lesson Video

This page supports the lesson note with a companion video and a short classroom-ready summary.

For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.

Performance objectives

• Identify the coordinates of points on the number plane.
• Construct a table of values from a given rule.
• Plot points accurately on the number plane.
• Understand the relationship between coordinates and tables.

Lesson summary

This lesson introduces learners to the number plane (also known as the Cartesian plane), a powerful tool used in mathematics to visualise relationships between two quantities. We will learn how to find "addresses" or locations on this plane using coordinates. We will also explore how to use a mathematical rule (a relation) to create a table of values and then use those values to plot points. This skill is very important; it is used in creating maps, tracking business profits, reading graphs in science, and even in computer programming and design. For instance, knowing how the cost of buying waakye changes with the number of scoops you buy is a real-life pattern we can show on a graph.

Lesson notes

Part 1: The Number Plane (The Cartesian Plane)

Think of the number plane as two number lines crossing each other. It's like a map for numbers. The x-axis: This is the horizontal number line. It runs from left to right. Positive numbers are on the right of the centre, and negative numbers are on the left. The y-axis: This is the vertical number line. It runs up and down. Positive numbers are above the centre, and negative numbers are below. The Origin: This is the special point where the x-axis and y-axis cross. Its "address" is (0, 0). It is our starting point for all counting.

Here is a simple sketch of the Number Plane:

``` ^ y-axis (Positive) | 3 | 2 | 1 | x-axis (Positive) -3 -2 -1 | 0 1 2 3 -1 | (Origin) -2 | -3 | v (Negative) (Negative) ``` Part 2: Coordinates - The Address of a Point