Last updated on May 26th, 2025
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 821.
The divisibility rule for 821 is a method by which we can determine if a number is divisible by 821 without using the division method. Let's check whether 1642 is divisible by 821 using the divisibility rule.
Step 1: Split the number into parts that are easy to manage. For 1642, consider 1, 6, 4, and 2 as separate components.
Step 2: Multiply each component by specific coefficients that come from the sequence of 821. In this case, imagine the sequence as 821, 8210, 82100, etc. You'd multiply: 1×821, 6×8210, 4×82100, and 2×821000.
Step 3: Add up all these products. If the sum is divisible by 821, then the original number is divisible by 821.
Learning divisibility rules helps kids master division. Here are a few tips and tricks for the divisibility rule of 821:
Memorize multiples of 821 (821, 1642, 2463, 3284, etc.) to quickly check divisibility. If the sum of products is a multiple of 821, the number is divisible by 821.
You can use division as a way to verify and cross-check your results. This will help you confirm your findings and also reinforce learning.
The divisibility rule of 821 helps us quickly check if a number is divisible by 821, but common mistakes like calculation errors can lead to incorrect conclusions. Here we will understand some common mistakes and how to avoid them.
Is 8610 divisible by 287?
Yes, 8610 is divisible by 287.
To check if 8610 is divisible by 287, follow these steps:
1) Take the last three digits of the number, which is 610.
2) Subtract this value from the number formed by the remaining digits, 8 - 610 = -602.
3) If -602 is divisible by 287, then 8610 is divisible by 287. Since -602 = -287 × 2 + 28, the result is not divisible by 287.
Check the divisibility rule of 287 for 5740.
No, 5740 is not divisible by 287.
Follow the steps to check if 5740 is divisible by 287:
1) Take the last three digits, which is 740.
2) Subtract this from the number formed by the remaining digit, 5 - 740 = -735.
3) Since -735 is not a multiple of 287, 5740 is not divisible by 287.
Is 861 divisible by 287?
Yes, 861 is divisible by 287.
To determine if 861 is divisible by 287:
1) Take the last three digits, which is 861 in this case.
2) Since there are no other digits, there's no need to subtract.
3) 861 is 287 multiplied by 3 (287 x 3 = 861), so it is divisible by 287.
Can 1722 be divisible by 287 following the divisibility rule?
No, 1722 isn't divisible by 287.
To check the divisibility of 1722 by 287:
1) Take the last three digits, which is 722.
2) Subtract this from the number formed by the remaining digit, 1 - 722 = -721.
3) Since -721 is not a multiple of 287, 1722 is not divisible by 287.
Check the divisibility rule of 287 for 574.
No, 574 is not divisible by 287.
To check if 574 is divisible by 287:
1) Take the last three digits, which is 574 in this case.
2) Since there are no other digits, there's no need to subtract.
3) 574 divided by 287 equals 2 with a remainder, so it is not divisible by 287.
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.
: She loves to read number jokes and games.