Divisibility Rule of 121

The divisibility rule for 121 is a method by which we can find out if a number is divisible by 121 without using the division method. Check whether 14641 is divisible by 121 with the divisibility rule.

Step 1: Break down the number 14641 into groups of three digits from the right. So, we have 641 and 14.

Step 2: Subtract the group on the left (14) from the group on the right (641), i.e., 641 - 14 = 627.

Step 3: If the result from step 2 is divisible by 121, then the original number is divisible by 121. Since 627 is not divisible by 121, 14641 is not divisible by 121.

Learning the divisibility rule will help kids master division. Let’s learn a few tips and tricks for the divisibility rule of 121.

• Know the multiples of 121: Memorize the multiples of 121 (121, 242, 363, 484, etc.) to quickly check the divisibility. If the result from the subtraction is a multiple of 121, then the number is divisible by 121.

• Repeat the process for large numbers: Students should keep repeating the divisibility process until they reach a small number that is either divisible by 121 or clearly not. For example, check if 14641 is divisible by 121 using the divisibility test. Break it into 641 and 14, then subtract: 641 - 14 = 627. Since 627 is not divisible by 121, 14641 is not divisible by 121.

• 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 121 are 121, 242, 363, etc.

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

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

• Verification: The process of checking and confirming whether a mathematical conclusion is correct, often using an alternative method such as division.