197 LearnersLast updated on May 26th, 2025
Divisibility Rule of 40
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 40.
What is the Divisibility Rule of 40?
The divisibility rule for 40 is a method by which we can find out if a number is divisible by 40 or not without using the division method. A number is divisible by 40 if it is divisible by both 5 and 8. Check whether 320 is divisible by 40 with the divisibility rule.
Step 1: Check divisibility by 5. A number is divisible by 5 if its last digit is 0 or 5. In 320, the last digit is 0, so 320 is divisible by 5.
Step 2: Check divisibility by 8. A number is divisible by 8 if the last three digits form a number that is divisible by 8. In 320, the last three digits form the number 320, which is divisible by 8 (320 ÷ 8 = 40).
Step 3: Since 320 is divisible by both 5 and 8, it is divisible by 40.
Tips and Tricks for Divisibility Rule of 40
Learning the divisibility rule will help kids master division. Let’s learn a few tips and tricks for the divisibility rule of 40.
- Know the multiples of 40: Memorize the multiples of 40 (40, 80, 120, 160, etc.) to quickly check divisibility.
- Check divisibility by 5 and 8: Ensure the number meets the criteria for divisibility by both 5 and 8.
- 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.
Common Mistakes and How to Avoid Them in Divisibility Rule of 40
The divisibility rule of 40 helps us quickly check if a given number is divisible by 40, but common mistakes like calculation errors lead to incorrect conclusions. Here we will understand some common mistakes that will help you to avoid them.
Mistake 1
Not checking both components (5 and 8).
Always ensure the number is divisible by both 5 and 8 to confirm divisibility by 40.
Divisibility Rule of 40 Examples
Problem 1
A box of chocolates contains 640 chocolates. Is this number divisible evenly among 40 friends if each friend is to receive an equal number of chocolates?
Yes, 640 is divisible by 40.
Explanation
To determine if 640 is divisible by 40:
1. Check if the number is divisible by both 5 and 8 (since 40 = 5 × 8).
2. The last digit of 640 is 0, so it is divisible by 5.
3. Take the last three digits (640), and divide by 8: 640 ÷ 8 = 80. Since 80 is an integer, 640 is divisible by 8.
4. Since 640 is divisible by both 5 and 8, it is divisible by 40.
Problem 2
You have 1,320 pages to distribute equally among 40 binders. Can this be done without splitting any pages?
Yes, 1,320 is divisible by 40.
Explanation
To check if 1,320 is divisible by 40:
1. Verify divisibility by both 5 and 8.
2. The last digit is 0, which means it's divisible by 5.
3. Take the last three digits (320), and divide by 8: 320 ÷ 8 = 40. Since 40 is an integer, 320 is divisible by 8.
4. Since 1,320 is divisible by both 5 and 8, it is divisible by 40.
Problem 3
A total of 3,280 oranges need to be packed into boxes, each holding 40 oranges. Will they fit perfectly?
Yes, 3,280 is divisible by 40.
Explanation
To determine if 3,280 is divisible by 40:
1. Check divisibility by both 5 and 8.
2. The last digit is 0, indicating divisibility by 5.
3. Take the last three digits (280), and divide by 8: 280 ÷ 8 = 35. Since 35 is an integer, 280 is divisible by 8.
4. Since 3,280 is divisible by both 5 and 8, it is divisible by 40.
Problem 4
You have a budget of $4,760 to evenly distribute as bonuses to 40 employees. Can each employee receive an equal bonus?
Yes, 4,760 is divisible by 40.
Explanation
To see if 4,760 is divisible by 40:
1. Verify divisibility by both 5 and 8.
2. The last digit is 0, so it is divisible by 5.
3. Take the last three digits (760), and divide by 8: 760 ÷ 8 = 95. Since 95 is an integer, 760 is divisible by 8.
4. Since 4,760 is divisible by both 5 and 8, it is divisible by 40.
Problem 5
Is a shipment of 2,100 items evenly divisible among 40 packages?
Yes, 2,100 is divisible by 40.
Explanation
To check if 2,100 is divisible by 40:
1. Check divisibility by both 5 and 8.
2. The last digit is 0, indicating divisibility by 5.
3. Take the last three digits (100), and divide by 8: 100 ÷ 8 = 12.5. Since 12.5 is not an integer, 100 is not divisible by 8.
4. Correcting the step for 2,100: 100 is not divisible by 8; hence the initial answer was incorrect. 2,100 is not divisible by 40 when corrected.
FAQs on Divisibility Rule of 40
1.What is the divisibility rule for 40?
2.How many numbers are there between 1 and 200 that are divisible by 40?
3.Is 160 divisible by 40?
4.What if a number is divisible by 5 but not by 8?
5.Does the divisibility rule of 40 apply to all integers?
6.How can children in India use numbers in everyday life to understand Divisibility Rule of 40?
7.What are some fun ways kids in India can practice Divisibility Rule of 40 with numbers?
8.What role do numbers and Divisibility Rule of 40 play in helping children in India develop problem-solving skills?
9.How can families in India create number-rich environments to improve Divisibility Rule of 40 skills?
Important Glossaries for Divisibility Rule of 40
- Divisibility rule: A set of rules used to find out whether a number is divisible by another number without direct division.
- Multiples: The results obtained by multiplying a number by an integer. For example, multiples of 40 are 40, 80, 120, 160, etc.
- Integers: Numbers that include all whole numbers, negative numbers, and zero.
- Divisible: A number is divisible by another if it can be evenly divided without a remainder.
- Verification: The process of confirming results by cross-checking using alternative methods, such as actual 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
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