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Last updated on May 26th, 2025

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Divisibility Rule of 321

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The divisibility rule is a way to find out whether a number is divisible by another number without using the division method. In real life, we can use the divisibility rule for quick math, dividing things evenly and sorting things. In this topic, we will learn about the divisibility rule of 321.

Divisibility Rule of 321 for US Students
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What is the Divisibility Rule of 321?

The divisibility rule for 321 is a method by which we can find out if a number is divisible by 321 or not without using the division method. Check whether 642 is divisible by 321 with the divisibility rule.

 

Step 1: Break the number into groups of three digits starting from the right. Here, 642 is already a three-digit number.

 

Step 2: Check if each group of three digits forms a number that is divisible by 321. If yes, then the entire number is divisible by 321.

 

Here, 642 ÷ 321 = 2 with no remainder, so 642 is divisible by 321.

divisibility rule of 321

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Tips and Tricks for Divisibility Rule of 321

Learning the divisibility rule will help kids master division. Let’s learn a few tips and tricks for the divisibility rule of 321.

 

 

Know the multiples of 321:

 Memorize the multiples of 321 (321, 642, 963, etc.) to quickly check divisibility. If the number formed by a group of three digits is a multiple of 321, then the entire number is divisible by 321.

 

 

Break down larger numbers:

 For larger numbers, break them into groups of three digits from right to left. Check each group separately for divisibility by 321.

 

 

Use the division method to verify:

 Students can use the division method as a way to verify and crosscheck their results. This will help them confirm and also learn.

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Common Mistakes and How to Avoid Them in Divisibility Rule of 321

The divisibility rule of 321 helps us to quickly check if the given number is divisible by 321, but common mistakes like calculation errors lead to incorrect calculations. Here we will understand some common mistakes that will help you to understand.

Mistake 1

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Not following the correct steps.

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Students should follow the correct steps of breaking the number into groups of three digits and checking each group for divisibility by 321.

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Divisibility Rule of 321 Examples

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Problem 1

Is 642 divisible by 321?

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Yes, 642 is divisible by 321.

Explanation

To determine if 642 is divisible by 321, we check the following:

1) Divide 642 by 321.

2) The result is exactly 2, with no remainder.

3) Therefore, 642 is divisible by 321.

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Max, the Girl Character from BrightChamps

Problem 2

Check the divisibility rule of 321 for 1284.

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Yes, 1284 is divisible by 321.

Explanation

To verify if 1284 is divisible by 321:

1) Divide 1284 by 321.

2) The quotient is 4, and there is no remainder.

3) Thus, 1284 is divisible by 321.

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Problem 3

Is -321 divisible by 321?

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Yes, -321 is divisible by 321.

Explanation

To determine if -321 is divisible by 321:

1) Consider the positive equivalent, 321.

2) 321 divided by 321 equals 1, with no remainder.

3) Hence, -321 is divisible by 321.

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Problem 4

Can 963 be divisible by 321 following the divisibility rule?

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Yes, 963 is divisible by 321.

Explanation

To check if 963 is divisible by 321:

1) Divide 963 by 321.

2) The quotient is 3, with no remainder.

3) Therefore, 963 is divisible by 321

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Max, the Girl Character from BrightChamps

Problem 5

Check the divisibility rule of 321 for 1605.

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No, 1605 is not divisible by 321.

Explanation

To verify if 1605 is divisible by 321:

1) Divide 1605 by 321.

2) The result is approximately 5, with a remainder.

3) Thus, 1605 is not divisible by 321.

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FAQs on Divisibility Rule of 321

1.What is the divisibility rule for 321?

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2.How many numbers are there between 1 and 1000 that are divisible by 321?

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3.Is 642 divisible by 321?

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4.What if a group of digits is exactly 321?

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5.Does the divisibility rule of 321 apply to all integers?

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6.How can children in United States use numbers in everyday life to understand Divisibility Rule of 321?

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7.What are some fun ways kids in United States can practice Divisibility Rule of 321 with numbers?

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8.What role do numbers and Divisibility Rule of 321 play in helping children in United States develop problem-solving skills?

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9.How can families in United States create number-rich environments to improve Divisibility Rule of 321 skills?

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Important Glossaries for Divisibility Rule of 321

  • Divisibility rule: The set of rules used to find out whether a number is divisible by another number or not. For example, a number is divisible by 321 if each group of three digits is divisible by 321.

 

  • Multiples: Multiples are the results we get after multiplying a number by an integer. For example, multiples of 321 are 321, 642, 963, etc.

 

  • Integers: Integers are the numbers that include all the whole numbers, negative numbers, and zero.

 

  • Grouping: Grouping is the process of dividing a number into parts, such as groups of three digits, for the purpose of applying a divisibility rule.

 

  • Verification: Verification involves using alternative methods, like division, to confirm the results obtained from a divisibility rule.
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About BrightChamps in United States

At BrightChamps, we believe numbers are more than symbols—they’re keys unlocking endless possibilities! Our goal is to help children across the United States build strong math skills, focusing today on the Divisibility Rule of 321 and especially on understanding the Divisibility Rule—delivered in a way that’s engaging, fun, and easy to grasp. Whether your child is calculating the speed of a roller coaster at Disney World, keeping score during Little League games, or managing their allowance for the newest gadgets, knowing numbers boosts their confidence for real-life situations. Our hands-on lessons make learning enjoyable and straightforward. Since kids in the USA learn in diverse ways, we customize our approach to match each learner’s style. From the lively streets of New York City to the sunny beaches of California, BrightChamps makes math relatable and exciting across America. Let’s make the Divisibility Rule an enjoyable part of every child’s math adventure!
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Hiralee Lalitkumar Makwana

About the Author

Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.

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Fun Fact

: She loves to read number jokes and games.

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