Class 8 CBSE Mathematics: Direct and Inverse Proportions PPTs
Free Download – All Chapters Included
Welcome to your one-stop destination for high-quality, classroom-ready Class 8 CBSE Mathematics PowerPoints. Whether you are a teacher looking for engaging lesson aids or a student aiming to simplify complex concepts, our chapter-wise PPTs are designed to make learning interactive and effective.
In this section, we focus on Chapter 11: Direct and Inverse Proportions, a vital topic that forms the backbone of commercial mathematics and physics.
📘 Understanding the Concept
The relationship between two quantities can change in two primary ways. Our PPTs break these down with real-world examples:
1. Direct Proportion
Two quantities $x$ and $y$ are said to be in direct proportion if they increase or decrease together such that the ratio $\frac{x}{y}$ remains constant.
Formula: $\frac{x_1}{y_1} = \frac{x_2}{y_2}$
Example: If the cost of 5 pens is ₹50, the cost of 10 pens will be ₹100. As quantity increases, cost increases.
2. Inverse Proportion
Two quantities $x$ and $y$ are in inverse proportion if an increase in $x$ causes a proportional decrease in $y$ (and vice versa) such that their product $xy$ remains constant.
Formula: $x_1y_1 = x_2y_2$
Example: If 4 workers finish a wall in 6 hours, 8 workers will finish it in 3 hours. As speed/workers increase, time decreases.
🚀 Key Features of Our PPTs
Step-by-Step Solutions: Every slide guides you through the logic of solving proportionality problems.
Visual Aids: Tables and graphs to help visualize the constant $k$.
Exam-Oriented Questions: Includes Important Questions from NCERT and previous CBSE papers.
Teacher-Friendly: Fully editable slides so you can add your own classroom notes or school logo.
📥 Download Links
Click the buttons below to download the presentations for Chapter 11 and all other Class 8 Maths chapters.
| Chapter Name | Download Link |
| Ch 11: Direct & Inverse Proportions | |
Pro Tip for Students: After downloading the PPT, try solving the practice questions on the final slide without looking at the solutions. This is the best way to ensure you've mastered the concept!
