Last updated on May 26th, 2025
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 3.
The divisibility rule for 3 is a method by which we can find out if a number is divisible by 3 or not without using the division method. Check whether 123 is divisible by 3 with the divisibility rule.
Step 1: Add up all the digits of the number. In 123, the digits are 1, 2, and 3, so add them: 1 + 2 + 3 = 6.
Step 2: Check if the result from Step 1 is a multiple of 3. Since 6 is a multiple of 3, 123 is divisible by 3. If the sum is not a multiple of 3, then the number isn't divisible by 3.
Learn divisibility rules to help kids master division. Let’s learn a few tips and tricks for the divisibility rule of 3.
Memorize the multiples of 3 (3, 6, 9, 12, 15, etc.) to quickly check the divisibility. If the sum of the digits is a multiple of 3, then the number is divisible by 3.
Students should keep repeating the divisibility process until they reach a small number that is easily recognized as a multiple of 3. For example, check if 1947 is divisible by 3 using the divisibility test. Add the digits: 1 + 9 + 4 + 7 = 21. Since 21 is a multiple of 3, 1947 is divisible by 3.
Students can use the division method as a way to verify and cross-check their results. This will help them to verify and also learn.
The divisibility rule of 3 helps us to quickly check if the given number is divisible by 3, but common mistakes like calculation errors lead to incorrect results. Here we will understand some common mistakes that will help you to avoid them.
Can the total number of fruits in a basket, 123, be divided evenly into three groups?
Yes, 123 is divisible by 3.
To check if 123 is divisible by 3, add the digits of the number: 1 + 2 + 3 = 6. Since 6 is a multiple of 3, 123 is divisible by 3.
Check if the number 456 can be split evenly among three friends.
Yes, 456 is divisible by 3.
Add the digits of 456: 4 + 5 + 6 = 15. Since 15 is a multiple of 3, 456 can be divided evenly by 3.
Is the total number of books, 789, divisible by 3?
Yes, 789 is divisible by 3.
Add the digits of 789: 7 + 8 + 9 = 24. Since 24 is a multiple of 3, 789 is divisible by 3.
Determine if the number 101 can be evenly divided by 3.
No, 101 is not divisible by 3.
Add the digits of 101: 1 + 0 + 1 = 2. Since 2 is not a multiple of 3, 101 is not divisible by 3.
Is the total score of a game, 372, divisible by 3?
Yes, 372 is divisible by 3.
Add the digits of 372: 3 + 7 + 2 = 12. Since 12 is a multiple of 3, 372 is divisible by 3.
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.
: She loves to read number jokes and games.