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Divisibility by 13:
How do you know that a number is divisible by 13? Well, this method of checking and verifying a number is different or unique. You need to do this one. Multiply the last digit of a given number by 4 and then add it to the remaining digits. If the result is a multiple of 13, then the given number is divisible by 13. You can repeat the process if you wish until the result is a multiple of 13.
Example 1:
The first thing that we need to do is to inspect the given number if it is divisible by 13 or not.
Multiply the last digit by 4 and then add it to the remaining digits as follows
Since 35 is not a multiple of 13, then the given number is not divisible by 13. There's a remainder of 3 in the division. The answer or a quotient must be a whole number itself. You should not have a fraction or a remainder in the final answer.
Example 2:
The first thing that we need to do is to inspect the given number if it is divisible by 13 or not.
Multiply the last digit by 4 and then add it to the remaining digits as follows
Since 26 is a multiple of 13, then the given number is divisible by 13. There's no remainder or a fraction in the division.
You should consider in studying the divisibility of a number because you will use these principles later when you will study higher Math subjects that involves the division of a number, simplifying fractions, and even factoring.
This method can also be used for negative integers as long as the result of a process is a multiple of 13. Again, there should be no remainder or a fraction in the division.