Grade 8
  1. Number Systems  1.1. Rational Numbers  1.2. Irrational Numbers  1.3. Real Numbers  1.4. Properties of Real Numbers  1.4.1. Commutative Property  1.4.2. Associative Property  1.4.3. Distributive Property  1.5. Representation on the Number Line  1.6. Operations on Real Numbers  1.6.1. Addition and Subtraction  1.6.2. Multiplication and Division  1.7. Rationalization  1.8. Exponents and Powers  1.9. Square Roots and Cube Roots
  2. Algebra  2.1. Algebraic Expressions  2.2. Identities and Simplification  2.2.1. Multiplying Binomials  2.2.2. Using Algebraic Identities  2.3. Factorization  2.3.1. Common Factors  2.3.2. Factorization by Grouping  2.3.3. Factorization of Trinomials  2.3.4. Special Products  2.4. Linear Equations in One Variable  2.4.1. Solving Linear Equations  2.4.2. Word Problems on Linear Equations
  3. Geometry  3.1. Understanding Quadrilaterals  3.1.1. Properties of Quadrilaterals  3.1.2. Types of Quadrilaterals  3.1.2.1. Parallelogram  3.1.2.2. Rectangle  3.1.2.3. Square  3.1.2.4. Rhombus  3.1.2.5. Trapezium  3.2. Constructions  3.2.1. Constructing Quadrilaterals  3.2.2. Constructing Bisectors  3.2.3. Constructing Angles  3.2.4. Constructing Triangles  3.3. Symmetry and Transformations  3.3.1. Reflection  3.3.2. Rotation  3.3.3. Translation  3.3.4. Symmetry in Patterns
  4. Mensuration  4.1. Area and Perimeter  4.1.1. Perimeter of Polygons  4.1.2. Area of Triangles  4.1.3. Area of Quadrilaterals  4.1.4. Area of Circles  4.2. Surface Area and Volume  4.2.1. Cubes  4.2.2. Cuboids  4.2.3. Cylinders  4.2.4. Cones  4.2.5. Spheres
  5. Data Handling  5.1. Organizing Data  5.2. Frequency Distribution Tables  5.3. Graphical Representation of Data  5.3.1. Bar Graphs  5.3.2. Histograms  5.3.3. Pie Charts  5.3.4. Line Graphs (added)  5.4. Probability  5.4.1. Introduction to Probability  5.4.2. Experimental Probability
  6. Coordinate Geometry  6.1. Cartesian Plane  6.2. Plotting Points  6.3. Coordinate System  6.4. Distance Between Points  6.5. Applications of Coordinate Geometry
  7. Introduction to Graphs  7.1. Linear Graphs  7.2. Applications of Graphs  7.3. Distance-Time Graphs  7.4. Speed-Time Graphs
  8. Comparing Quantities  8.1. Ratio and Proportion  8.2. Percentage  8.2.1. Increase and Decrease Percent  8.2.2. Discount in Percentage  8.2.3. Profit and Loss in Percentage  8.2.4. Simple Interest  8.2.5. Compound Interest
  9. Exponents and Powers  9.1. Laws of Exponents  9.2. Negative Exponents  9.3. Standard Form  9.4. Applications of Exponents
  10. Introduction to Squares and Square Roots  10.1. Properties of Square Numbers  10.2. Finding Square Roots  10.2.1. Prime Factorization Method  10.2.2. Division Method  10.3. Estimating Square Roots
  11. Introduction to Cubes and Cube Roots  11.1. Properties of Cube Numbers  11.2. Finding Cube Roots  11.2.1. Prime Factorization Method in Finding Cube Roots

Grade 8 → Introduction to Graphs ↓


Applications of Graphs


Graphs are everywhere around us. They play a vital role in various fields as they provide a visual way to represent and understand the relationships between different quantities. Using graphs, we can easily understand and solve real-world problems.

1. Understanding the graph

A graph is a diagram that shows relationships between different quantities or numbers. The most common types of graphs you'll encounter include line graphs, bar graphs, and pie charts.

1.1 Line graph

Line graphs are used to display data that changes over time. They help us see trends in data by connecting individual data points with lines.

It is a simple line graph that shows a trend. The x-axis usually represents time, while the y-axis represents the quantity measured.

1.2 Bar graph

Bar graphs are used to compare quantities or numbers. Each bar represents a category of data, and the height or length of the bar represents the value of that data.

This bar graph compares three categories. Each color can represent a different group, such as favorite food, number of pets, or test scores.

1.3 Pie chart

Pie charts show parts of a whole as slices of a circle. They are useful for displaying percentage or proportional data.

This pie chart can show the percentage distribution of time spent on various activities, such as sleep, work, exercise, leisure, and meals, during a day.

2. Applications of graphs in the real world

Graphs are very important tools for representing data. They help us understand numbers, patterns, and changes. Let's take a look at some applications of graphs in different fields.

2.1 Science and engineering

In science and engineering, graphs help visualize experimental results, understand complex patterns, and predict future outcomes. For example, in physics, a velocity-time graph shows how the speed of an object changes over time.

 Velocity-time graph example:
,
| Time (seconds) | Velocity (meter/second) |
,
| 0 | 0 |
| 1 | 10 |
| 2 | 20 |
| 3 | 30 |
,

2.2 Business and economics

Graphs play an important role in business and economics by providing information about financial performance or market trends. Businesses use graphs to analyze sales data, track performance, and make informed decisions. Stock price line graphs are a common representation of economic data.

This graph can show the fluctuations in a stock price over a period, where the decline and rise reflect the market performance.

2.3 Health and medicine

In health and medicine, graphs help monitor patients' vital signs, track the spread of diseases, and assess the effectiveness of treatments. For example, a heart rate graph can show how a patient's heart rate changes during different activities.

 Heart rate graph example:
,
| Time (minutes) | Heart rate (beats/minute) |
,
| 0 | 70 |
| 5 | 100 |
| 10 | 110 |
| 15 | 90 |
,

2.4 Education

In education, graphs are used to display the results of assessments or surveys, helping teachers understand students' progress, performance, and areas that need improvement. A test score bar graph can show how students performed in different subjects.

The bar graph above can compare marks in Maths, Science and English, and provide an overview of the class's performance in these subjects.

3. Drawing a graph

Creating a graph involves identifying the type of graph that best represents the data and then accurately drawing or plotting the graph. This process can be done manually or using software.

3.1 Steps to draw a line graph

  1. Identify the variables: Determine what data will be plotted on the x-axis and the y-axis.
  2. Create the axes: Create an x-axis (horizontal) and a y-axis (vertical), labeling each with the appropriate units.
  3. Plot the data points: For each pair of values, plot a point on the graph that corresponds to those values.
  4. Connect the points: Draw straight lines between each point to complete the graph.
  5. Title and labels: Add a title and necessary labels to make the graph easier to understand.

3.2 Example

Let's draw a line graph using the following data:

Year | Sales ($K)
,
2018 | 20
2019 | 30
2020 | 40
2021 | 35

To create a line graph:

  • The X-axis will represent the years 2018 to 2021.
  • The Y-axis should show sales in thousands.
2018 2019 2020 2021

This line graph shows the sales trend over four years, showing an increase until 2020 and a slight decline in 2021.

3.3 Tips for effective graphs

  • Keep it simple. Avoid cluttering the graph with unnecessary details.
  • Use consistent scale on axes for easier interpretation.
  • Choose colors that stand out from each other.
  • Label your graph clearly to avoid confusion.
  • Use a legend if different colors or patterns represent different data sets.

4. Conclusion

Graphs are an indispensable tool for representing and understanding complex data. They help us see patterns, make decisions, and communicate information effectively. By learning how to interpret and create graphs, we can better analyze and visualize the world around us.

Graphs touch various fields and serve as a bridge between raw data and meaningful insights. They simplify information, allowing us to understand complexities quickly and efficiently. Whether in science, business, health or education, graphs are a fundamental part of our everyday lives, helping us make informed decisions every day.


Grade 8 → 7.2


U
username
0%
completed in Grade 8

← Prev (7.1)
Linear Graphs
Next (7.3) →
Distance-Time Graphs

Comments 



Applications of Graphs

https://www.buddymath.com/g8/7.2?bmal=en