Divisibility Rule of 129

The divisibility rule for 129 is a method by which we can find out if a number is divisible by 129 or not without using the division method. Check whether 387 is divisible by 129 with the divisibility rule.

Step 1: Break down 129 into its prime factors, which are 3 and 43.

Step 2: Check divisibility by 3: Add up all the digits of the number. For 387, the sum is 3 + 8 + 7 = 18. Since 18 is divisible by 3, 387 passes this test.

Step 3: Check divisibility by 43: Use the division method for verification since there is no simple rule for 43. Divide 387 by 43. If the quotient is a whole number, it is divisible by 43.

Since 387 ÷ 43 = 9, which is a whole number, 387 is divisible by 43.

Since 387 is divisible by both 3 and 43, it is divisible by 129.

Learning the divisibility rule will help kids to master division. Let’s learn a few tips and tricks for the divisibility rule of 129.

• Know the prime factors: Memorize the prime factors of 129 (3 and 43) to quickly check the divisibility. Ensure the number is divisible by both 3 and 43.
   
• Use addition for 3: For divisibility by 3, add the digits of the number. If the sum is a multiple of 3, then the number is divisible by 3.
   
• Use division for 43: Use the division method to verify divisibility by 43 as there is no simple rule for it.
   
• Repeat the process for large numbers: For large numbers, repeat the process to ensure divisibility by both factors. 
   
• Verify with division: You can use the division method to verify and crosscheck results, ensuring accuracy.

• Divisibility Rule: The set of rules used to determine if a number is divisible by another number without performing direct division.
   
• Prime Factors: The prime numbers that multiply together to give a particular number.
   
• Integer: Whole numbers that can be positive, negative, or zero.
   
• Sum of Digits: The total obtained by adding all the digits of a number, used to check divisibility by certain factors.
   
• Division Method: A method of dividing numbers to verify divisibility, often used for factors without simple rules.