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146 LearnersLast updated on February 17th, 2025
Divisibility Rule of 121
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 121.
What is the 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.
Tips and Tricks for Divisibility Rule of 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.
Common Mistakes and How to Avoid Them in Divisibility Rule of 121
The divisibility rule of 121 helps us to quickly check if a given number is divisible by 121, but common mistakes like calculation errors lead to incorrect conclusions. Here we will understand some common mistakes that will help you avoid them.
Mistake 1
Not following the correct steps.
Students should follow the correct steps by breaking the number into groups of three digits and subtracting them as described.
Divisibility Rule of 121 Examples
Problem 1
A farmer has 605 apples and wants to pack them into boxes, each holding the same number of apples. Is it possible for each box to contain 121 apples?
Yes, 605 is divisible by 121.
Explanation
We can check the divisibility by dividing 605 by 121.
1) Divide 605 by 121, which equals exactly 5.
2) Since the division results in an integer with no remainder, 605 is divisible by 121.
Problem 2
A concert hall has 726 seats. The manager wants to divide these seats into sections of equal size, with each section containing 121 seats. Can this be done?
No, 726 is not divisible by 121.
Explanation
We verify by dividing 726 by 121.
1) Divide 726 by 121, which gives approximately 6.004.
2) Since this results in a non-integer, 726 is not divisible by 121.
Problem 3
A library received a donation of 1214 books and wants to distribute them evenly among various shelves, with each shelf holding 121 books. Is this possible?
Yes, 1214 is divisible by 121.
Explanation
Check divisibility by performing the division.
1) Divide 1214 by 121, which equals exactly 10.
2) Since the division results in an integer with no remainder, 1214 is divisible by 121.
Problem 4
A teacher has 100 students and wants to form groups, with each group having 121 students. Can this be achieved?
No, 100 is not divisible by 121.
Explanation
We determine this by attempting the division.
1) Divide 100 by 121, resulting in approximately 0.826.
2) Since this is not an integer, 100 is not divisible by 121.
Problem 5
A bakery produced 2420 loaves of bread and plans to package them in boxes, each containing 121 loaves. Is this possible?
Yes, 2420 is divisible by 121.
Explanation
Confirm divisibility through division.
1) Divide 2420 by 121, which equals exactly 20.
2) Since the result is an integer with no remainder, 2420 is divisible by 121.
FAQs on Divisibility Rule of 121
1.What is the divisibility rule for 121?
2.How many numbers are there between 1 and 1000 that are divisible by 121?
3.Is 121 divisible by 121?
4.What if I get 0 after subtracting?
5.Does the divisibility rule of 121 apply to all integers?
Important Glossaries for Divisibility Rule of 121
- 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.
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Hiralee Lalitkumar Makwana
About the Author
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.
Fun Fact
: She loves to read number jokes and games.
