CBSE Class 8 Maths Formulas: Algebra, Euler’s & more

Maths Formulas for Class 8: Sometimes, it can be tough for a Class 8 student to grasp concepts of Mathematics. To get a high level of knowledge, students must first learn 8th Class Maths formulas and then move towards solving questions. One could question where to obtain the correct Maths formulae for Class 8 for a certain collection of problems. Thus, we have provided all Maths formulae for Class 8 on this page so that students do not encounter any difficulties.

The topic-wise CBSE Class 8 Maths formulae are accessible for download on Embibe. Our best Mathematics tutors have created these formulas more simply. Check arithmetic, algebraic, Euler’s, and more formulas for Class 8 from this page. These formulas will help you solve problems quickly and earn more points in CBSE Class 8 exams. Read on to find more.

NCERT Maths Formulas for Class 8

Many students argue about the fact that Maths formulas are hard to grasp. However, if you understand the meaning of the formulas, practice them regularly, and solve a sufficient number of questions, all the formulas will be at your fingertips.

CBSE Class 8 Maths has the following chapters:

• Chapter-1: Rational Numbers
• Chapter-2: Linear Equation in One Variable
• Chapter-3: Understanding Quadrilaterals
• Chapter-4: Practical Geometry
• Chapter-5: Data Handling
• Chapter-6: Square and Square Roots
• Chapter-7: Cube and Cube Roots
• Chapter-8: Comparing Quantities
• Chapter-9: Algebraic Expressions and Identities
• Chapter-10: Mensuration
• Chapter-11: Exponents and Power
• Chapter-12: Direct and Inverse Proportion
• Chapter-13: Factorization
• Chapter-14: Introduction to Graphs
• Chapter-15: Playing with Numbers

Let’s take a look at some of the important chapter-wise lists of Maths formulas for Class 8.

Learn 8th CBSE Exam Concepts

Maths Class 8 Formulas: Rational Numbers

Any number that can be written in the form of p ⁄ q where q ≠ 0 are rational numbers. It possesses the properties of:

1. Additive Identity: (a ⁄ b + 0) = (a ⁄ b)
2. Multiplicative Identity: (a ⁄ b) × 1 = (a/b)
3. Multiplicative Inverse: (a ⁄ b) × (b/a) = 1
4. Closure Property – Addition: For any two rational numbers a and b, a + b is also a rational number.
5. Closure Property – Subtraction: For any two rational numbers a and b, a – b is also a rational number.
6. Closure Property – Multiplication: For any two rational numbers a and b, a × b is also a rational number.
7. Closure Property – Division: Rational numbers are not closed under division.
8. Commutative Property – Addition: For any rational numbers a and b, a + b = b + a.
9. Commutative Property – Subtraction: For any rational numbers a and b, a – b ≠ b – a.
10. Commutative Property – Multiplication: For any rational numbers a and b, (a x b) = (b x a).
11. Commutative Property – Division: For any rational numbers a and b, (a/b) ≠ (b/a).
12. Associative Property – Addition: For any rational numbers a, b, and c, (a + b) + c = a + (b + c).
13. Associative Property – Subtraction: For any rational numbers a, b, and c, (a – b) – c ≠ a – (b – c)
14. Associative Property – Multiplication: For any rational number a, b, and c, (a x b) x c = a x (b x c).
15. Associative Property – Division: For any rational numbers a, b, and c, (a / b) / c ≠ a / (b / c) .
16. Distributive Property: For any three rational numbers a, b and c, a × ( b + c ) = (a × b) +( a × c).

Number Formation

1. A two-digit number ‘ab’ can be written in the form: ab = 10a + b
2. A three-digit number ‘abc’ can be written as: abc = 100a+10b+c
3. A four-digit number ‘abcd’ can be formed: abcd = 1000a+100b+10c+d

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Maths Formulas For Class 8: Laws of Exponents

1. a⁰ = 1
2. a^-m = 1/a^m
3. (a^m)ⁿ = a^mn
4. a^m / aⁿ = a^m-n
5. a^m x b^m = (ab)^m
6. a^m / b^m = (a/b)^m
7. (a/b)^-m =(b/a)^m
8. (1)ⁿ = 1 for infinite values of n.

Maths Formulas For Class 8: Algebraic Identity

Algebraic Identities comprises of several equality equations which consist of different variables.

• a) Linear Equations in One Variable: A linear equation in one variable has the maximum one variable of order 1. It is depicted in the form of ax + b = 0, where x is the variable.
• b) Linear Equations in Two Variables: A linear equation in two variables has the maximum of two variables of order 2. It is depicted in the form of ax² + bx + c = 0.

1. (a + b)² = a² + 2ab + b²
2. (a – b)² = a² – 2ab + b²
3. (a + b) (a – b) = a² – b²
4. (x + a) (x + b) = x² + (a + b)x + ab
5. (x + a) (x – b) = x² + (a – b)x – ab
6. (x – a) (x + b) = x² + (b – a)x – ab
7. (x – a) (x – b) = x² – (a + b)x + ab
8. (a + b)³ = a³ + b³ + 3ab(a + b)
9. (a – b)³ = a³ – b³ – 3ab(a – b)

Maths Formulas for Class 8: Square & Square Roots

If a natural number, m = n² and n is a natural number, then m is said to be a square number.

1. Every square number surely ends with 0, 1, 4, 5 6 and 9 at its units place.
2. A square mysqladmin is the inverse operation of the square.

Formula of Maths Class 8: Cube & Cube Roots

Numbers, when obtained while multiplied by itself three times, is known as cube numbers.

1. If every number in the prime factorization appears three times, then the number is a perfect cube.
2. The symbol of the cube is ∛.
3. Cube and Cube mysqladmin: ∛27 = 3 and 3³ = 27.

Class 8th Maths Formulas: Comparing Quantities

Discounts are the reduction value prevailed on the Marked Price (MP).

• Discount = Marked Price – Sale Price
• Discount = Discount % of the Marked Price

Overhead expenses are the additional expenses made after purchasing an item. These are included in the Cost Price (CP) of that particular item.

• CP = Buying Price + Overhead Expenses

GST (Goods and Service Tax) is calculated on the supply of the goods.

• Tax = Tax % of the Bill Amount

Compound Interest (CI) is the interest which is compounded on the basis of the previous year’s amount.

Formula of Amount (Compounded Annually): \(A = P \left (1 + \frac{R}{100} \right )^t\)

P = Principal,
r = Rate of Interest, and
t = Time Period

Formula of Amount (Compounded Half Yearly): \(A = P \left (1 + \frac{R}{200} \right )^{2t}\)

R/2 = Half-yearly Rate,
2t = Number of Half-Years

Maths Formulas for Class 8: Data Handling & Probability

Any useful information that can be utilized for some specific use is known as Data. These data can be represented either graphically (Pictograph/Bar Graph/Pie Charts) or symmetrically (Tabular form). Find the important Class 8 Maths formulas for Data Handling and Probability.

1. A class interval is the specific range of numbers such as 10-20, 20-30, 30-40, and so forth.
2. For a Class Interval of 10-20, Lower Class Limit = 10 and Upper-Class Limit = 20
3. Frequency is the number of times a particular value occurs.

Probability = Number of Favourable Outcomes / Total Number of Outcomes

Math Formula Class 8: Geometry

Here, we will define the geometrical formulas consistently used in Mathematics Class 8. We will use the following abbreviations for convenience:

• 1. LSA – Lateral/Curved Surface Area
• 2. TSA – Total Surface Area

CHECK THE DETAILED MATHS SYLLABUS FOR CLASS 8

List of Important Class 8 Math Formulas  

Consistent practise is essential for success in math. Students are encouraged to solve as many problems as they can, since this will expose them to a variety of formulas. This is a fantastic technique to recall formulas without having to mumble them down. Here is a summarized list of Class 8 math formulas that can be used.

1. Additive inverse of rational number: a/b = -b/a
2. Multiplicative Inverse of a/b = c/d , if a/b × c/d = 1
3. Distributivity a(b – c) = ab – ac
4. Probability of the occurrence of an event = Number of outcomes that comprise an event/ Total number of outcomes
5. Compound Interest formula = Amount – Principal, Amount in case the interest is to be calculated annually = Principal ( 1 + Rate/100)ⁿ, where ‘n’ is the time period.
6. (a – b)² = a² – 2ab + b²
7. (a + b) (a – b) = a² – b²  
8. Euler’s Formula: For any polyhedron, Number of faces + Number of vertices – Number of edges = 2
9. Volume of a Cone = (1 / 3 )πr²h
10. Volume of a Sphere = (4/3) π r³

Practice 8th CBSE Exam Questions

FAQs on CBSE Class 8 Maths Formulas

Here are some important frequently asked questions related to Class 8 Maths formulas.

Q: How to memorize Class 8 Maths formulas?
A: Just refer to the formula sheet as you solve questions. Eventually, you will memorize them and master their application.

Q: Is NCERT enough for the Class 8 Maths exam?
A: Yes, for Class 8, the NCERT Maths textbook is enough.

Q: Which book should I prefer for learning Class 8 maths formulas?
A: We advise you to go for NCERT books if you want to know all the important Class 8 Maths formulas.

Q: Is there any website that offers free Class 8 practice questions?
A: Embibe provides free Class 8 practice questions to learn and score well in your examinations.

Q: How to make the best use of these maths formulas?
A: These Class 8 Maths formulas will help you when you get stuck in some questions while practising the subject. The formulas and properties will help you in quick revision. This way you can prepare well and score better.

Q: How will these Class 8 maths formulas help me?
A: These Maths formulas are taken from the standard Class 8 NCERT book. Therefore, it’ll prove to be useful for you no matter what education board you are studying in. These formulas are present on a page so that you don’t have to go back and forth. Hence, this will come in handy at the time of revision.

These are some of the important maths formulas for Class 8. These will prove to be helpful in making your journey a rather easy one. Solve the free Class 8 Maths Mock Test and refer to these formulas when necessary. With passing time, you will improve.

If you have any queries, feel free to comment them down and we will get back to you. Embibe wishes you all the best!