 # Factors of 21

Factors of 21 are the numbers that divide the original number 21 completely without leaving the remainder. Factors of 21 are 1, 3, 7, and 21. Kids must learn to recognize the factors of 21 that divide the number evenly by leaving the remainder zero. Kids can learn how to find the factors of a number by using simple division and multiplication methods. Also, make sure that you make learning interesting for kids with math activities. These activities help them understand the concept while having fun. Moreover, it develops mathematical skills in children.

Contents

Sometimes, kids might get confused about the factors of numbers and ways to calculate them. In such cases, you need to teach kids factors of 21 using creative methods and help them understand the concept better. The best way would be to conduct math games for kids where they get to learn factors of 21 effectively. The pair factors of 21 can be positive or negative numbers but cannot be decimal or fraction numbers. Besides this, teach kids to find the prime and pair factors of 21 using the division and multiplication methods, respectively.

Check math-related articles:

## What are the Factors of 21?

Factors of 21 are obtained when you divide the original number 21 with the integers completely without leaving the remainder. The factors of 21 are 1, 3, 7, and 21. Since the number 21 is a composite number, it has two factors other than one and the number itself. To teach kids the difference between pair and prime factors of 21, you need to teach them how to calculate the pair and prime factors of 21 using multiplication and prime factorization methods. The pair factors of 21 are (1 x 21) and (3 x 7), whereas the negative pair factors of 21 are (-1 x -21) and (-3 x -7). The prime factors of 21 are 3 x 7, and it is obtained by dividing the original number with the prime numbers until you get a quotient one. There are four factors of 21 and the total sum is 1 + 3 + 7 + 21 = 32.

## How to Find the Factors of 21?

How will you teach kids to calculate the factors of 21? We are here to help you provide an easy method to find the factors of 21. You need to divide the original number 21 by the integers to get factors of 21 without leaving the remainder. In addition, learning a multiplication table for kids helps them calculate the factors of 21 accurately. Check out the following division method to find the factors of 21.

21/1 = 21

21/3 = 7

21/7 = 3

21/21 = 1

Therefore, the factors of 21 are 1, 3, 7, and 21.

### Pair Factors of 21

Pair factors of 21 are the numbers obtained when you multiply two numbers together to get the result as the original number. The numbers can be positive or negative pair factors. You can teach kids to find the pair factors of 21 using the multiplication method. Check out the following method to find the pair factors of 21.

1 x 21 = 21

3 x 7 = 21

7 x 3 = 21

21 x 1 = 21

Therefore, the pair factors of 21 are (1, 21) and (3, 7). However, you can also calculate the negative pair factors of 21 using the multiplication method. When two negative factors multiply together, the result you get is positive. Check the following method to calculate the negative pair factors of 21.

-1 x -21 = 21

-3 x -7 = 21

-7 x -3 = 21

-21 x -1 = 21

Therefore, the negative pair factors of 21 are (-1, -21) and (-3, -7).

### Prime Factors of 21

Prime factors of 21 are the numbers obtained when you divide the original number by the prime numbers until you get a quotient one. Check out the prime factorization method to find the prime factors of 21 given below.

Step 1: Divide the original number with the least prime number 2.

21/2 = 10.5

Step 2: Since the original number is not divisible by prime number 2, you take prime number 3.

21/3 = 7

Step 3: Divide the number 7 with the prime number 7 to get the quotient 1.

7/7 = 1

Therefore, the prime factors of 21 are 3 x 7.

## Solved Examples on Factors of 21

Some solved examples on factors of 21 are mentioned below.

Example 1: Find the common factors of 16 and 21.

Solution: Factors of 16 = 1, 2, 4, 8, and 16.

Factors of 21 = 1, 3, 7, and 21

Therefore, the common factor of 16 and 21 is 1.

Example 2: Sarah had 21 popsicle sticks, and she divided them equally among her 3 friends. How many popsicle sticks did each of them receive?

Solution: Number of popsicle sticks = 21

Number of friends = 3

Total number of popsicle stickers received by each friend = 21/3 = 7

Therefore, the total number of popsicle sticks received by each friend is 7.

Example 3: Find the common factors of 20 and 21.

Solution: Factors of 20 = 1, 2, 4, 5, 10, and 20.

Factors of 21 = 1, 3, 7, and 21

Therefore, the common factor of 20 and 21 is 1.

Check multiplication tables related articles

## Benefits of Learning Factors of 21

The benefits of learning factors of 21 for kids are mentioned below:

• It improves children’s knowledge of factors of 21 to solve related mathematical problems accurately.
• It develops mathematical skills in children.
• It encourages children to practice equations or problems regularly to attain mastery of the concept.
• It increases their academic scores in mathematics and other topics dealing with factors of 21.
• It boosts children’s confidence to enjoy learning mathematics creatively.

We hope this article on factors of 21 was useful to you. For more about activities, worksheets and games, explore worksheets for kids, math for kidspuzzles for kids, kids learning sections at Osmo.

## Frequently Asked Questions on Factors of 21

### What are the factors of 21?

The factors of 21 are 1, 3, 7, and 21

### What are the pair factors of 21?

The pair factors of 21 are (1, 21) and (3, 7).

### What are the prime factors of 21?

The prime factors of 21 are 3 x 7.