Divisibility Rule of 421

The divisibility rule for 421 is a method by which we can find out if a number is divisible by 421 or not without using the division method. Check whether 842 is divisible by 421 with the divisibility rule.

Step 1: Divide the number into groups of three digits starting from the right. If the last group is smaller than three digits, consider it as it is. Here, 842 is already one group.

Step 2: Check if the number in each group is divisible by 421. In our case, check if 842 is divisible by 421.

Step 3: If all groups are divisible by 421, then the entire number is divisible by 421. If not, then the number isn't divisible by 421.

Learning the divisibility rule will help kids to master division. Let’s learn a few tips and tricks for the divisibility rule of 421.

Know the multiples of 421:

Memorize the multiples of 421 (421, 842, 1263, 1684…etc.) to quickly check divisibility. If the number in the group is a multiple of 421, then the number is divisible by 421.

Use smaller numbers:

If the number is smaller than 421, directly check if it is 421 or 0.

Repeat the process for large numbers:

Students should keep dividing the number into groups and checking each group until they confirm divisibility by 421.

Example: Check if 1684 is divisible by 421 using the divisibility test. Divide 1684 into groups: 1 and 684. Check each group. 684 is 421 × 1 + 263 (not divisible), so the number is not divisible by 421.

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.
 

• 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.
   
• Integer: Integers are numbers that include all the whole numbers, negative numbers, and zero.
   
• Remainder: The amount left over after division when one number does not divide another exactly.
   
• Grouping: The process of dividing a number into parts for easier calculation and analysis.