Divisibility Rule of 189

The divisibility rule for 189 is a method by which we can find out if a number is divisible by 189 or not without using the division method. Check whether 1701 is divisible by 189 with the divisibility rule.  

Step 1: Check if the number is divisible by 9. Add the digits of the number, and if the sum is divisible by 9, then the number is divisible by 9. For 1701, 1+7+0+1=9, which is divisible by 9.

Step 2: Check if the number is divisible by 21. Check if the number is divisible by both 3 and 7. For 1701, the sum of the digits is 9, which is divisible by 3, and for 7, subtract twice the last digit from the rest of the number (170-2*1=168), which is divisible by 7.

Step 3: Since 1701 is divisible by both 9 and 21, it is divisible by 189.

Learning the divisibility rule will help kids to master division. Let’s learn a few tips and tricks for the divisibility rule of 189.

• Know the multiples of 189: Memorize the multiples of 189 (189, 378, 567, 756…etc.) to quickly check for divisibility.

• Use the divisibility rules for 9 and 21: Check if a number is divisible by 9 and 21; if both conditions are met, the number is divisible by 189.

• Repeat the process for large numbers: Students should keep repeating the divisibility process until they reach a small number that is divisible by 189. For example: Check if 3402 is divisible by 189. First, check for divisibility by 9: 3+4+0+2=9, which is divisible by 9. Then check for divisibility by 21: 340-2*2=336, which is divisible by 21.

• Use the division method to verify: 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.

• 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 189 are 189, 378, 567, etc.

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

• Addition: The process of calculating the total of two or more numbers or amounts.

• Subtraction: Subtraction is a process of finding out the difference between two numbers, by reducing one number from another.