Divisibility Rule of 801

The divisibility rule for 801 is a method by which we can find out if a number is divisible by 801 without using the division method. Check whether 2403 is divisible by 801 with the divisibility rule.

Step 1: Multiply the last digit of the number by 2; here in 2403, 3 is the last digit, so multiply it by 2. 3 × 2 = 6

Step 2: Subtract the result from Step 1 from the remaining values, but do not include the last digit. i.e., 240–6 = 234.

Step 3: Repeat the process to ensure the number is small enough to check easily. Multiply the last digit of 234 by 2, 4 × 2 = 8. Subtract this from the remaining number, 23–8 = 15.

Step 4: Since 15 is not a multiple of 801, the original number 2403 is not divisible by 801. If the result from the repeated steps were 0 or a multiple of 801, the number would be divisible by 801.

Learning the divisibility rule helps kids master division. Let’s learn a few tips and tricks for the divisibility rule of 801.

Know the multiple of 801:

Memorize the multiples of 801 (801, 1602, 2403, etc.) to quickly check divisibility. If the result from the subtraction process matches one of these multiples, the number is divisible by 801.

Use negative numbers:

If the result we get after subtraction is negative, we will ignore the symbol and consider it as positive for checking the divisibility of a number.

Repeat the process for large numbers:

Students should keep repeating the divisibility process until they reach a small number that is divisible by 801. For example, check if 4812 is divisible by 801 using the divisibility test. Multiply the last digit by 2, i.e., 2 × 2 = 4. Subtract the remaining digits excluding the last digit by 4, 481–4 = 477. Repeat the process: 7 × 2 = 14, 47–14 = 33. Since 33 is not a multiple of 801, 4812 is not divisible by 801.

Use the division method to verify:

Students can use the division method to verify and cross-check their results. This will help them verify and also learn.

• Divisibility rule: A set of rules used to determine whether a number is divisible by another number.

• Multiples: Results obtained by multiplying a number by an integer, e.g., multiples of 801 are 801, 1602, 2403, etc.

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

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

• Verification: The process of confirming the accuracy of a result, such as using division to confirm divisibility.