Selina Concise Mathematics Class 8 ICSE Solutions Chapter 21 – Surface Area, Volume and Capacity (Cuboid, Cube and Cylinder)
Surface Area, Volume and Capacity is one of the most practical and scoring chapters in Selina Concise Mathematics Class 8 ICSE. This chapter introduces students to three-dimensional geometry and teaches how to calculate the space occupied by solid objects. Students learn formulas related to cuboids, cubes, and cylinders along with their practical applications in daily life. The chapter improves numerical ability, visualization skills, and understanding of measurement concepts. By practicing the exercise-wise solutions regularly, students can strengthen their problem-solving skills and perform confidently in school examinations.
Find the PDF of all exercises of Selina Concise Mathematics Class 8 ICSE Solutions chapter-21-Surface Area, Volume and Capacity (Cuboid, Cube and Cylinder)
Understanding Surface Area and Volume
The ICSE Class 8 chapter begins with the concepts of surface area and volume. Students learn that surface area refers to the total area covered by the outer surfaces of a solid figure, while volume represents the space occupied inside the object.
The solutions explain these concepts using practical examples from daily life such as boxes, containers, tanks, and cylinders. Students understand how measurements are applied in real-world situations. The chapter focuses on conceptual clarity so students can solve numerical problems accurately and confidently. Understanding the difference between surface area and volume is extremely important because both concepts are used frequently in higher mathematics and science.
Surface Area and Volume of a Cuboid
A major part of the chapter focuses on cuboids. Students learn formulas for lateral surface area, total surface area, and volume of a cuboid. The exercise questions help students understand how length, breadth, and height affect calculations. The solutions explain each step carefully so students can avoid common mistakes while substituting values into formulas. Numerical problems based on practical situations improve analytical thinking and calculation speed.
Students also learn unit conversions while solving volume and capacity questions, which is a very important skill in examinations.
Understanding Cube Calculations
The chapter also explains the properties of cubes and how they differ from cuboids. Since all edges of a cube are equal, students learn simplified formulas for calculating surface area and volume.
Practice questions based on cubes help students improve their understanding of geometric relationships and measurements. The solutions are written in a step-by-step manner, making calculations easy to follow and revise. Regular practice of cube-related questions improves accuracy and strengthens confidence in handling geometry-based numerical problems.
Surface Area and Volume of Cylinder
The cylinder section introduces students to curved surfaces and circular measurements. Students learn how to calculate curved surface area, total surface area, and volume of cylinders using formulas involving radius and height.
The chapter explains practical applications of cylinders such as water tanks, pipes, and containers. Students understand how mathematics is used in everyday objects and measurements. Exercise-wise solutions help students solve complex questions systematically and improve their ability to apply formulas correctly during examinations.
Capacity and Unit Conversions
One of the most practical topics in the chapter is capacity measurement. Students learn the relationship between volume and capacity along with unit conversions involving litres and cubic units.
These concepts are important because many examination questions combine geometry and measurement together. Students learn how to convert units correctly and solve practical word problems involving storage and liquid quantities. Regular practice of such problems improves logical thinking and reduces calculation mistakes.
Importance of Exercise-Wise Solutions
Exercise-wise solutions are extremely useful for students because geometry and mensuration problems require step-by-step calculations. The solutions explain formulas, substitutions, and unit conversions clearly.
Students can identify mistakes easily and understand the correct solving methods through detailed explanations. Regular practice of textbook exercises improves speed, accuracy, and confidence for school examinations. The chapter becomes easier to revise when students use organized exercise-wise solutions regularly.
Tips to Score High in Chapter 21
Students should first memorize all important formulas related to cuboids, cubes, and cylinders. Understanding the meaning of each formula is equally important for solving application-based questions. Careful attention should be given to units while solving numerical problems. Students should also practice unit conversions regularly because they are commonly asked in examinations. Writing formulas clearly before calculations and solving problems step-by-step can improve presentation and reduce mistakes in exams.