151 LearnersLast updated on May 26th, 2025
Divisibility Rule of 85
The divisibility rule is a way to determine 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 85.
What is the Divisibility Rule of 85?
The divisibility rule for 85 helps us determine if a number is divisible by 85 without performing division. Check whether 2890 is divisible by 85 with the divisibility rule.
Step 1: Check if the number is divisible by both 5 and 17. For 2890, since the last digit is 0, it is divisible by 5.
Step 2: Add the digits of the number to see if the sum is divisible by 17. 2 + 8 + 9 + 0 = 19, which is not divisible by 17.
Since 2890 is divisible by 5 but not by 17, it is not divisible by 85.
Tips and Tricks for Divisibility Rule of 85
Learning the divisibility rule will help kids master division. Let’s learn a few tips and tricks for the divisibility rule of 85.
- Know the multiples of 85: Memorize the multiples of 85 (85, 170, 255, 340, ... etc.) to quickly check divisibility. If both conditions (divisibility by 5 and 17) are met, the number is divisible by 85.
- Use the sum of the digits for 17: To check divisibility by 17, the sum of the digits of the number should be checked. If it is a multiple of 17, the number is divisible by 17.
- Repeat the process for large numbers: Students should keep repeating the divisibility process for large numbers to ensure accuracy.
For example: Check if 3400 is divisible by 85 using the divisibility test. The last digit is 0, so it is divisible by 5. Adding the digits, 3 + 4 + 0 + 0 = 7, which is not divisible by 17. Thus, 3400 is not divisible by 85.
- Use the division method to verify: Students can use the division method 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 85
The divisibility rule of 85 helps us to quickly check if a given number is divisible by 85, but common mistakes like calculation errors can lead to incorrect conclusions. Here we will understand some common mistakes that will help you avoid them.
Mistake 1
Not checking divisibility by both 5 and 17.
Ensure the number satisfies divisibility rules for both 5 and 17.
Divisibility Rule of 85 Examples
Problem 1
Is 425 divisible by 85?
Yes, 425 is divisible by 85.
Explanation
To check if 425 is divisible by 85, apply the following steps:
1) Divide the number by 5 to check if it's divisible by 5, 425 ÷ 5 = 85.
2) Now check if 85 is divisible by 17 (since 85 = 5 x 17).
3) 85 ÷ 17 = 5, which is a whole number. Therefore, 425 is divisible by 85.
Problem 2
Check the divisibility rule of 85 for 1700.
Yes, 1700 is divisible by 85.
Explanation
To check if 1700 is divisible by 85, follow these steps:
1) Divide the number by 5 to check if it's divisible by 5, 1700 ÷ 5 = 340.
2) Now check if 340 is divisible by 17.
3) 340 ÷ 17 = 20, which is a whole number. Therefore, 1700 is divisible by 85.
Problem 3
Is 510 not divisible by 85?
Yes, 510 is not divisible by 85.
Explanation
To determine divisibility, perform the following steps:
1) Divide the number by 5 to check divisibility, 510 ÷ 5 = 102.
2) Check if 102 is divisible by 17.
3) 102 ÷ 17 = 6 with a remainder, so 510 is not divisible by 85.
Problem 4
Can 850 be divisible by 85 following the divisibility rule?
Yes, 850 is divisible by 85.
Explanation
To check if 850 is divisible by 85, follow these steps:
1) Divide the number by 5 to check divisibility, 850 ÷ 5 = 170.
2) Now check if 170 is divisible by 17.
3) 170 ÷ 17 = 10, which is a whole number. Therefore, 850 is divisible by 85.
Problem 5
Check the divisibility rule of 85 for 1530.
No, 1530 is not divisible by 85.
Explanation
To determine divisibility, use the following process:
1) Divide the number by 5 to check divisibility, 1530 ÷ 5 = 306.
2) Check if 306 is divisible by 17.
3) 306 ÷ 17 = 18 with a remainder, so 1530 is not divisible by 85.
FAQs on Divisibility Rule of 85
1.What is the divisibility rule for 85?
2.How many numbers are there between 1 and 1000 that are divisible by 85?
3.Is 255 divisible by 85?
4.What if the sum of digits is 0 after adding?
5.Does the divisibility rule of 85 apply to all integers?
6.How can children in United States use numbers in everyday life to understand Divisibility Rule of 85?
7.What are some fun ways kids in United States can practice Divisibility Rule of 85 with numbers?
8.What role do numbers and Divisibility Rule of 85 play in helping children in United States develop problem-solving skills?
9.How can families in United States create number-rich environments to improve Divisibility Rule of 85 skills?
Important Glossaries for Divisibility Rule of 85
- Divisibility rule: The set of rules used to determine whether a number is divisible by another number or not. For example, a number is divisible by 5 if its last digit is 0 or 5.
- Multiples: Multiples are results obtained by multiplying a number by an integer. For example, multiples of 85 are 85, 170, 255, 340, etc.
- Integers: Integers are numbers that include all whole numbers, negative numbers, and zero.
- Sum of digits: The process of adding all the digits of a number together.
- Verification: The process of using division to confirm the result of a divisibility test.
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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.
