Lesson Notes By Weeks and Term v5 - Grade 10

Patterns, relationships and representations – Week 9 focus

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Subject: Mathematical Literacy

Class: Grade 10

Term: 1st Term

Week: 9

Theme: General lesson support

Lesson Video

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Performance objectives

Lesson summary

This week, we delve into the fascinating world of patterns, relationships, and representations. These aren't just abstract mathematical concepts; they're fundamental to understanding the world around us, from predicting monthly expenses to interpreting crime statistics or analyzing the spread of disease. In South Africa, understanding patterns can help us analyze social trends, manage resources effectively, and make informed decisions about our lives and communities.

Lesson notes

2.1 What are Patterns, Relationships and Representations?

Patterns: A pattern is a discernible regularity in data or a series of events. Patterns can be numerical (sequences of numbers), geometric (shapes), or even qualitative (recurring behaviors). We look for consistency and predictability within these observations.

Relationships: A relationship describes how two or more variables are connected. These connections can be simple (direct proportion) or complex (inverse relationships, exponential growth). Understanding these relationships enables us to predict changes in one variable based on changes in another.

Representations: Representation refers to how we display or communicate patterns and relationships. This includes tables of values, graphs (bar graphs, pie charts, line graphs, scatter plots), algebraic equations, and even written descriptions. The choice of representation depends on the type of data and the message we want to convey. 2.2 Types of Patterns: Linear Patterns: A linear pattern exhibits a constant difference between consecutive terms. The general form of a linear equation is y = mx + c, where m represents the constant difference (slope) and c is the starting value (y-intercept).

Quadratic Patterns: In a quadratic pattern, the second difference between consecutive terms is constant. The general form is y = ax² + bx + c. These patterns often represent situations involving areas or projectile motion.

Exponential Patterns: Exponential patterns show a constant ratio between consecutive terms. This means the terms are multiplied by the same factor each time. The general form is y = a b^x, where b is the constant ratio (growth or decay factor).

Geometric Patterns: These patterns involve shapes that follow a specific rule to create the next shape in the sequence. Often, the number of elements (sides, area, volume) in these shapes will follow a numerical pattern (linear, quadratic, or exponential). 2.3 Discrete vs.

Continuous Data: Discrete Data: Discrete data can only take on specific, separate values. Usually, these are whole numbers. Examples include the number of students in a class, the number of cars passing a point on a highway in an hour, or the number of goals scored in a soccer match.

Continuous Data: Continuous data can take on any value within a given range. Examples include height, weight, temperature, or time. We can measure continuous data with arbitrary precision. 2.4 Representing Data: Tables: Tables organize data into rows and columns, making it easy to see specific values and compare data points.

Graphs: Graphs provide a visual representation of data, highlighting trends and relationships. Different types of graphs are suitable for different types of data.

Bar Graphs: Useful for comparing discrete categories.

Pie Charts: Show proportions of a whole.

Line Graphs: Display trends over time or show relationships between two continuous variables.

Scatter Plots: Illustrate the relationship between two continuous variables; can indicate correlation.

Algebraic Expressions: Equations and formulas provide a concise way to represent patterns and relationships mathematically. 2.5

Examples: Example 1: Linear Pattern - Taxi Fare A taxi charges a fixed call-out fee of R25 plus R8 per kilometer traveled.

Pattern: The total cost increases by R8 for each additional kilometer.

Relationship: The relationship between the distance traveled and the total cost is linear.

Representation: Table: | Distance (km) | Total Cost (R) | |---------------|----------------| | 0 | 25 | | 1 | 33 | | 2 | 41 | | 3 | 49 | | 4 | 57 | Graph: (A line graph with distance on the x-axis and total cost on the y-axis. The line starts at (0, 25) and has a slope of 8).

Algebraic Expression: Total Cost = 8 Distance + 25 If you travel 10 km, the total cost is 8 * 10 + 25 = R

1

0

5. Example 2: Quadratic Pattern - Number of Seats in a Stadium A section of a stadium has rows of seats where the number of seats in each row increases according to a quadratic pattern. The first three rows have 4, 7, and 12 seats respectively.

Pattern: The number of seats doesn't increase by a constant amount. Let's find the differences. 7 - 4 = 3, and 12 - 7 =

5. Since the first differences aren't constant, let's find the second difference. 5 - 3 =

2. Since the second difference is constant, we know this is a quadratic pattern.

Relationship: The relationship between the row number and the number of seats is quadratic.

Representation: Table: | Row Number | Number of Seats | First Difference | Second Difference | |------------|-----------------|------------------|-------------------| | 1 | 4 | | | | 2 | 7 | 3 | | | 3 | 12 | 5 | 2 | | 4 | 19 | 7 | 2 | | 5 | 28 | 9 | 2 | We found the next two terms by adding the constant second difference to the first difference and then adding the new first difference to the number of seats.

Example 3: Exponential Pattern - Population Growth A small town in the Eastern Cape has a population of 5000 people.