Divisibility Rule of 381

The divisibility rule for 381 is a method by which we can find out if a number is divisible by 381 or not without using the division method. Check whether 762 is divisible by 381 with the divisibility rule.

Step 1: Multiply the last digit of the number by 2, here in 762, 2 is the last digit. Multiply it by 2. 2 × 2 = 4

Step 2: Subtract the result from Step 1 from the remaining values but do not include the last digit. i.e., 76 - 4 = 72.

Step 3: As 72 is not a multiple of 381, the number is not divisible by 381. If the result from step 2 were a multiple of 381, then the number would be divisible by 381.

Learning the divisibility rule will help kids to master the division. Let’s learn a few tips and tricks for the divisibility rule of 381.

• Know the multiples of 381: Memorize the multiples of 381 (381, 762, 1143, 1524…etc.) to quickly check the divisibility. If the result from the subtraction is a multiple of 381, then the number is divisible by 381.
   
• Use the negative numbers: If the result we get after the subtraction is negative, we will avoid the symbol and consider it as positive for checking the divisibility of a number.
   
• Repeat the process for large numbers: Students should keep repeating the divisibility process until they reach a small number that is divisible by 381. For example: Check if 1143 is divisible by 381 using the divisibility test. Multiply the last digit by 2, i.e., 3 × 2 = 6. Subtract the remaining digits excluding the last digit by 6, 114 - 6 = 108. 
  
  Still, 108 is not a multiple of 381, so 1143 is not divisible by 381.
   
• 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 to verify and also learn.

• Divisibility rule: The set of rules used to find out whether a number is divisible by another number or not.
   
• Multiples: Multiples are the results we get after multiplying a number by an integer. For example: multiples of 381 are 381, 762, 1143, 1524, etc.
   
• Integers: Integers are the numbers that include all the whole numbers, negative numbers, and zero.
   
• Subtraction: Subtraction is a process of finding out the difference between two numbers by reducing one number from another.
   
• Verification: The process of using an alternative method, such as division, to confirm the results obtained from the divisibility rule.