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Last updated on March 29th, 2025

Multiples of 21

Q: How do you find the multiples of 21?

To find out the multiples of 21, we need to multiply 21 by any natural number. Natural numbers include 1, 2, 3,...etc. The results will be multiples of 21. Multiples of 21 will be larger or equal to 21. 21 × 1 = 21 21 × 2 = 42 21 × 3 = 63 21 × 4 = 84 21 × 5 = 105

Q: What is the LCM of 7 and 21?

LCM of 7 and 21 is 21. LCM refers to the Least Common Multiple of two or more numbers. While we find out the LCM of 7 and 21 using the listing method, we need to list the multiples of both 7 and 21. Multiples of 7 are 7, 14, 21, 28, 35, 42, 49, 56, 63, 70,… Multiples of 21 are 21, 42, 63, 84, 105, 126, 147, 168, 189,… Here, the smallest common number that appears in both lists is 21. LCM of 7 and 21 = 21.

Q: What are the real-life applications of Multiples of 21?

Multiples of 21 can be helpful in various real-life situations. We can use it for calculating the price of items, evaluating the value of multiple items, and organizing a number into groups.

Q: Are multiples of 21 finite or infinite?

All the multiples of 21 are infinite. In multiplication, every number has infinite multiples, including a multiple of itself. There are both positive and negative multiples of 21. When we calculate 21 × n, if the integer ‘n’, goes on forever, the multiples of 21 also become infinite.

Q: Is there any odd multiple of 21?

Yes, there are odd numbers in the multiples of 21. Since 21 is an odd number, multiplying it with an odd number will result in another odd number. For example, 21 × 1 = 21 21 × 3 = 63 21 × 5 = 105

Professor Greenline Explaining Math Concepts

Foundation

Intermediate

Advance Topics

In math, multiples are the products we get while multiplying a number with other numbers. Multiples play a key role in construction and design, counting groups of items, sharing resources equally, and managing time effectively. In this topic, we will learn the essential concepts of multiples of 21.

What are the Multiples of 21?

Now, let us learn more about multiples of 21. Multiples of 21 are the numbers you get when you multiply 21 by any whole number, along with zero. Each number has an infinite number of multiples, including a multiple of itself. In multiplication, a multiple of 21 can be denoted as 21 × n, where ‘n’ represents any whole number (0, 1, 2, 3,…). So, we can summarize that:

Multiple of a number = Number × Any whole number

For example, multiplying 21 × 1 will give us 21 as the product. Multiples of 21 will be larger or equal to 21. $Multiples of 21$

List of First 20 Multiples of 21

Multiples of 21 include the products of 21 and an integer. Multiples of 21 are divisible by 21 evenly. The first few multiples of 21 are given below:

TABLE OF 21 (1-10)
21 x 1 = 21	21 x 6 = 126
21 x 2 = 42	21 x 7 = 147
21 x 3 = 63	21 x 8 = 168
21 x 4 = 84	21 x 9 = 189
21 x 5 = 105	21 x 10 = 210

TABLE OF 21 (11-20)
21 x 11 = 231	21 x 16 = 336
21 x 12 = 252	21 x 17 = 357
21 x 13 = 273	21 x 18 = 378
21 x 14 = 294	21 x 19 = 399
21 x 15 = 315	21 x 20 = 420

Now, we know the first few multiples of 21. They are 0, 21, 42, 63, 84, 105, 126, 147, 168, 189, 210,...

Operations with Multiples of 21

Understanding the multiples of 21 helps solve mathematical problems and boost our multiplication and division skills. When working with multiples of 21, we need to apply it to different mathematical operations such as addition, subtraction, multiplication, and division.

Sum of first 5 Multiples of 21:

21, 42, 63, 84, and 105 are the first five multiples of 21. When multiplying 21 from 1 to 5 we get these numbers as the products.
So, the sum of these multiples is:

21 + 42 + 63 + 84 + 105 = 315

When we add the first 5 multiples of 21 the answer will be 315.

Subtraction of first 5 Multiples of 21:

While we do subtraction, it improves our comprehension of how the value decreases when each multiple is subtracted from the previous one. 21, 42, 63, 84, and 105 are the first five multiples of 21. So, let us calculate it as given below:

21 - 42 = -21
-21 - 63 = -84
-84 - 84 = -168
-168 - 105 = -273

Hence, the result of subtracting the first 5 multiples of 21 is -273.

Average of first 5 Multiples of 21:

To calculate the average, we need to identify the sum of the first 5 multiples of 21, and then divide it by the count, i.e., 5. Because there are 5 multiples presented in the calculation. Averaging helps us to understand the concepts of central tendencies and other values. We know the sum of the first 5 multiples of 21 is 315.

21 + 42 + 63 + 84 + 105 = 315

Next, divide the sum by 5:

315 ÷ 5 = 63

63 is the average of the first 5 multiples of 21.

Product of First 5 Multiples of 21:

The product of given numbers is the result of multiplying all of them together. Here, the first 5 multiples of 21 include: 21, 42, 63, 84, and 105. Now, the product of these numbers is:

21 × 42 × 63 × 84 × 105 = 234,256,320

The product of the first 5 multiples of 21 is 234,256,320.

Division of First 5 Multiples of 21:

While we perform division, we get to know how many times 21 can fit into each of the given multiples. 21, 42, 63, 84, and 105 are the first 5 multiples of 21.

21 ÷ 21 = 1
42 ÷ 21 = 2
63 ÷ 21 = 3
84 ÷ 21 = 4
105 ÷ 21 = 5

The results of dividing the first 5 multiples of 21 are: 1, 2, 3, 4, and 5.

Common Mistakes and How to Avoid Them in Multiples of 21

Multiples of 21 Examples

Ray, the Character from BrightChamps Explaining Math Concepts

Problem 1

In a music class, each session lasts for 21 minutes. If the music teacher conducts 5 sessions in a day, how many minutes of music lessons does the class receive in total?

Ray, the Boy Character from BrightChamps Saying "Let’s Begin"

Explanation

Problem 2

A vineyard produces wine bottles in batches that are multiples of 21. If the vineyard prepares the first three batches, how many wine bottles are produced?

Explanation

Problem 3

A farmer plants 21 trees in each row of his orchard. If there are 6 rows, how many trees does the farmer plant in total?

Explanation

Problem 4

During a charity event, volunteers create gift bags. Each gift bag contains 21 items. If 7 gift bags are prepared, how many items are there in total?

Explanation

Problem 5

In a library, new magazines are added in multiples of 21. The first shelf has 21 magazines, the second has 42, and the third has 63. How many magazines are there on these three shelves?

Explanation

FAQs on Multiples of 21

1.How do you find the multiples of 21?

2.What is the LCM of 7 and 21?

3.What are the real-life applications of Multiples of 21?

4.Are multiples of 21 finite or infinite?

5.Is there any odd multiple of 21?

Important Glossaries for Multiples of 21

Multiple: A multiple represents the product of a number that may be multiplied by an integer. For example, multiples of 21 include 21, 42, 63, 84, etc.
Number pattern: This refers to how numbers are listed. It should follow a certain sequence. Multiples of 21 are the numbers that consist of the number pattern of 21.
Odd number: An odd number refers to any number that cannot be evenly divided by 2. The last digits of odd numbers are 1, 3, 5, 7, or 9. Multiples of 21 can include odd numbers.
Divisor: It refers to any number by which another number can be divided without leaving any remainder. 1, 3, 7, and 21 are the divisors of 21.
LCM (Least Common Multiple): The smallest multiple that is exactly divisible by two or more numbers. For example, the LCM of 7 and 21 is 21.

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Seyed Ali Fathima S

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Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.