## Revision Notes for CBSE Class 8 Maths Chapter 7 - Free PDF Download

## FAQs on Cubes and Cube Roots Class 8 Notes CBSE Maths Chapter 7 [Free PDF Download]

1. What are cube numbers according to Revision Notes of Chapter 7 of Class 8 Maths?

The numbers which are obtained by multiplying themselves three times are called cube numbers. For example, 2 multiplied by itself three times gives 8 hence 8 is the cube of 2. When doing prime factorization of a cube number if a prime factor repeats itself 3 times then that number is called a perfect cube. There are only ten perfect cubes among 1-1000. The concept of cube numbers is important and students should practice the questions of this chapter thoroughly.

2. What are cube roots as described in Revision Notes of Chapter 7 of Class 8 Maths?

Cube roots of a number are the numbers which when multiplied by themselves give the cube of a number. The cube root of a number, for example, 8 is denoted by 38. Memorising cube roots of some commonly used numbers can help students in quicker calculations.

3. How do you find the cube root of a number?

The cube root of a number can be found out by the prime factorization method.

To find the cube root of a number follow these steps-

For example, if you want to find the cube root of 8000,

8000 = 2222225 55

Therefore,

38000= 225

225= 20is the cube root of 8000.

Prime factorization can be used to find the cube root when we do not know whether a number is a cube or not.

4. How many exercises are there in NCERT Chapter 7 of Class 8 Maths?

There are two exercises in the Chapter 7 of NCERT Class 8 Maths textbook:

Exercise 7.1- four questions

Exercise 7.1 tests the students' understanding of perfect cubes and how to find them.

Exercise 7.2- three questions

In this exercise, students will learn how to find the cube root of a number using the prime factorization method.

They will also solve problems of finding the cube root of a number using the estimation method.

5. What are the main topics in NCERT Chapter 7 of Class 8 Maths?

The Chapter 7 of NCERT Class 8 Maths textbook teaches students the concept of cube numbers and cube roots. Students will learn what are cube numbers and when are the cube numbers called perfect cubes. They will also learn the concept of cube roots. The important topic in this chapter is the methods of finding cube roots of a number using the prime factorization method. Another method that can be used is the estimation method for the numbers that are already known to be cube numbers. The students can get the solutions and notes on Vedantu website and Vedantu Mobile app for free.