Tuesday , February 25 2020 # NCERT 5th Class (CBSE) Mathematics: Factors And Multiples

#### A. Factors are the numbers that are multiplied to give a product.

5×4 = 20

5 and 4 are factors of 20.

factors of number also divide that number without leaving any remainder.

24÷3 = 8 (8 and 3 are both factors of 24.)

#### B. When you multiply a number by 1,2,3,4, …, the products are all multiples of the number.

For example, 3, 6, 9, 12, are all multiples of 3, as (3×1), (3×2), (3×3), (3×4).

#### C. Rules of Divisibility

The rules of divisibility will help you find which numbers divide others without leaving any remainder.

A number is divisible by
If the last digit is
2
0, 2, 4, 6, 8
5
0, 5
10
0
A number is divisible by
If the Sum of the digits is divisible by

#### D. Prime Numbers and Composite Numbers

The numbers 2, 3, 5, 7, …, have only two factors each – the number itself and the numbers 1. Such numbers are called prime numbers.

A prime number is any number greater than 1 that has only two factors – the number itself and the number 1.

6 has 4 factors. They are 1, 2, 3, and 6.

6 is called a composite number.

A composite number is any number greater than 1 that has more than different factors.

1 is a special number. It is neither prime nor composite.

## 10th Class CBSE Mathematics 2018-19

10th Class CBSE Mathematics 2018-19 Time: 3 hours M.M.: 80 Class: 10th Subject: Mathematics Date: 07/03/2019 …