Divisibility Rule of 7

The divisibility rule for 7 is a method by which we can find out if a number is divisible by 7 or not without using the division method. Check whether 203 is divisible by 7 with the divisibility rule.

Step 1: Multiply the last digit of the number by 2, here in 203, 3 is the last digit multiply it by 2. 3 × 2 = 6 

Step 2: Subtract the result from Step 1 with the remaining values but do not include the last digit. i.e., 20–6 = 14.

Step 3: As it is shown that 14 is a multiple of 7, therefore, the number is divisible by 7. If the result from step 2 isn't a multiple of 7 then the number isn't divisible by 7

Learn divisibility rule will help kids to master the division. Let’s learn a few tips and tricks for divisibility rule of 7. 

• Know the multiples of 7: Memorize the multiples of 7 (7,14,21,28,35…etc.) to quickly check the divisibility. The result from the subtraction is a multiple of 7 then the number is divisible by 7 

• Use the negative numbers: If the result we get after the subtraction is negative, we will avoid 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 7 .

For example: Check if 1946 is divisible by 7 using the divisibility test.

Multiply the last digit by 2, i.e., 6 × 2 = 12 

Subtract the remaining digits excluding the last digit by 12, 194–12 = 182 

Still, 182 is a large number, hence we will repeat the process again and multiply the last digit by 2, 2 × 2 = 4. 

Now subtracting 4 from the remaining numbers excluding the last digit, 18–4 = 14.

As 14 is a multiple of 7, 1946 is divisible by 7 

• Use the division method to verify:  Students can use the division method as a way to verify and crosscheck 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. For example, a number is divisible by 2 if the number ends with even numbers. 

• Multiples: Multiples are the results we get after multiplying a number by an integer. For example: multiples of 7 are 7,14,21,28…….

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

• Subtraction: Subtraction is a process of finding out the difference between two numbers, by reducing one number from another.

• Divisor: Divisor is a number that divides another number completely, leaving the remainder 0.