CBSE Class 9 Maths Important Formulas PDF (Chapter-Wise Important Terms and Formulae)

Mathematics for CBSE Class 9 introduces many foundational concepts that serve as building blocks for higher classes. Topics such as algebraic identities, the surface areas and volumes of 3D shapes, and various theorems in geometry rely heavily on specific formulas. Having these formulas organized in a single, accessible document like a PDF is a highly effective way for students to approach their studies. It eliminates the need to search through multiple chapters and textbooks during revision, allowing for more focused and efficient learning.
This type of resource is not just for rote memorization. By having all the key formulas in one place, students can better understand the connections between different mathematical concepts. Regularly reviewing these formulas helps reinforce their application, which is crucial for solving complex problems accurately and quickly during exams. For a student, a well-structured formula PDF is a confidence booster and a reliable companion throughout the academic year.

Check: CBSE Class 9 Maths Syllabus 2025–26

CBSE Class 9 Maths Units & Marks Distribution

The Class 9 Mathematics syllabus is organized into six key units. Each unit is assigned a specific mark weightage that contributes to the final theory paper. The following table outlines the distribution:

CBSE Class 9 Maths Important Formulas

Number System Formulas

Class 9 Math formulas for the Number System focus on crucial facts about rational and irrational numbers, which are fundamental for a strong mathematical base. For instance, if 'a' is a rational number and 'b' is an irrational number, then their sum (a + b) and difference (a - b) will always be irrational. Similarly, their product (ab) and quotient (a/b) will also be irrational numbers, provided that 'b' is not equal to zero.

• √ab = √a √b
• √(a/b) =  √a / √b
• (√a + √b) (√a - √b) = a - b 
• (√a + √b)² = a + 2√ab + b
• (a + √b) (a - √b) = a² - b
• (a + b) (a - b) = a² - b²

Algebra Formulas

The fundamental properties and theorems of polynomials form the building blocks for higher algebra. Understanding polynomials, particularly the process of factorization, is crucial for finding the roots of equations. This foundational knowledge significantly enhances students' comprehension of algebra and prepares them for more advanced mathematical concepts.

• (a + b)² = a² + 2ab + b²
• (a - b)³ = a³ - b³ - 3ab(a - b)

Area and Volume Formulas

We come across shapes of all sorts in our daily life, and hence, the need to find their measurements arise, further leading to calculations of area and volume. These calculations are required in daily life whether one needs to figure out how much liquid is needed to fill a container or one needs to calculate the surface area of any object. The class 9 maths formulas regarding the same can be found as below:

• Area of a Rectangle: Length × Breadth

• Perimeter of a Rectangle: 2 × (Length + Breadth)

• Area of a Square: Side × Side

• Perimeter of a Square: 4 × Side

• Area of a Triangle: (1/2) × Base × Height

• Area of a Parallelogram: Base × Height

• Area of a Rhombus: (1/2) × d1 × d2 (where d1 and d2 are the diagonals)

• Area of a Trapezium: (1/2) × (Sum of parallel sides) × Height

• Circumference of a Circle: 2πr

• Area of a Circle: πr²

• Volume of a Cuboid: Length × Breadth × Height

• Surface Area of a Cuboid: 2(lb + bh + hl)

• Volume of a Cube: Side³

• Surface Area of a Cube: 6 × Side²

• Volume of a Cylinder: πr²h

• Curved Surface Area of a Cylinder: 2πrh

• Total Surface Area of a Cylinder: 2πr(r + h)

• Volume of a Cone: (1/3)πr²h

• Curved Surface Area of a Cone: πrl (where l is slant height)

• Total Surface Area of a Cone: πr(r + l)

• Volume of a Sphere: (4/3)πr³

• Surface Area of a Sphere: 4πr²

• Volume of a Hemisphere: (2/3)πr³

• Curved Surface Area of a Hemisphere: 2πr²

• Total Surface Area of a Hemisphere: 3πr²

Statistics and Probability Formulas 

Statistics and probability are fundamental in understanding data and making predictions. The ability to analyze data is crucial for drawing meaningful conclusions. The following formulas are essential for Class 9 students to grasp these concepts:

• Mean (Ungrouped Data): Sum of all observations / Number of observations

• Median (Ungrouped Data - Odd Number of Observations): [(n + 1)/2]th observation (where n is the number of observations)

• Median (Ungrouped Data - Even Number of Observations): [(n/2)th observation + (n/2 + 1)th observation] / 2

• Mode: The observation that occurs most frequently in the data.

• Probability of an Event (E): Number of favorable outcomes / Total number of possible outcomes

• P(E) + P(not E) = 1

Tips to Memorize Class 9 Maths Formulas

1. To truly understand and remember Class 9 Maths formulas, it's important to use them often by solving various problems. The more you practice, the easier it will be to recall these formulas quickly.
2. You can find images of these formulas online and use them as your phone or computer wallpaper. This way, every time you use your device, you'll see the formulas, helping you revise them throughout the day.
3. Studying with friends can also be very helpful. You can clear up any confusion together and make learning easier by sharing different ideas and approaches.

Also Check|

NCERT Book for Class 9 Maths ( Latest Edition)

NCERT Solutions for Class 9 Maths (Updated)