# Mathematics - Class 4 / Grade 4

- Types of Numbers / Kinds of Numbers
### Types of Numbers / Kinds of Numbers

Math - Class 4 – Types of Numbers / Kinds of Numbers- Key Points/Notes/Worksheets/Explanation/Lesson/Practice Questions Tags - Kinds of Numbers, Types of Numbers, Even Numbers, Odd Numbers, Prime Numbers, Twin Prime Numbers, Co- Prime Numbers, Composite Numbers, Prime Factorization Method, Factor Tree Method, Fact about Numbers, Prime, composite, even, odd, worksheet PDF, Quiz on numbers, Write the prime and composite numbers, Write the prime factors for the number, Write all the odd numbers between 20 and 30, Write all the prime numbers between 40 and 50Various Types of Numbers

Even Numbers

Any whole number which is exactly divisible by 2 is called an even number.

Example: 2, 4, 6, 8, 10 ……..etc. are even numbers.

OR

Any number in which digit at ones place is 0, 2, 4, 6, or 8 is an even number.

Example: 148, 222, 436, 120, 444 are even numbers.

OR

Even number is a number that can be divided into pairs of 2

Odd Numbers

Any whole number which cannot be exactly divisible by 2 is called an odd number.

Example: 1, 3, 5, 7, 9 ……..etc. are odd numbers.

OR

Any number in which digit at ones place is 1, 3, 5, 7, or 9 is an odd number.

Example: 141, 223, 435, 127, 449 are odd numbers.

OR

Odd number is a number that cannot be divided into pairs of 2

Prime Numbers

Number which has only two factors i.e. 1 and the number itself is called prime number.

Example: 2, 3, 5, 7, 11, 13, 17, 19, 23 etc. are prime numbers.

Twin Prime Numbers

Two prime numbers whose difference is 2 are called twin prime numbers.

Example: 3 and 5, 17 and 19

Co-prime Numbers

Any two numbers are considered as co-prime, if they do not have common factor other than 1. Co-prime number need not be necessarily prime numbers.

Example: 4 and 5

Composite Numbers

Number which has more than two factors is called composite number.

Example: 4, 6, 8, 9, 10, 12 etc. are composite numbers.

Prime Factorization Method

It is a method of finding all the prime numbers which multiply to make the given number.

**Method 1:****Factor Tree Method**

Example:32 = 2 x 2 x 2 x 2 x 2

__Explanation:__8 x 4 = 32, write factor 8 and 4 below 32

2 x 4 = 8, write factor 2 and 4 below 8

2 x 2 = 4, write factor 2 and 2 below 2

2 x 2 = 4, write factor 2 and 2 below 2

Now, we cannot factor further, so prime factor are the last number at each node.

**Method 2: Prime Factorization Method**Example:

32 = 2 x 2 x 2 x 2 x 2

__Explanation:__Start dividing 32 by the smallest prime number i.e. 2

32 ÷ 2 = 16

16 is composite number, so divide 16 again by 2

16 ÷ 2 = 8

8 is composite number, so divide 8 again by 2

8 ÷ 2 = 4

4 is composite number, so divide 4 again by 2

4 ÷ 2 = 2

2 is prime number

Point to be remembered

1. Composite number can be written as a product of its prime factors.

Example: 24 = 2 x 2 x 2 x 3

2. No two numbers can have the same prime factors.

Example: 24 = 2 x 2 x 2 x 3 and 32 = 2 x 2 x 2 x 2 x 2

3. 1 is neither a prime number nor a composite number.

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