Consider an arithmetic division of a number by an integer which may be from 2 to 10. We have obviously excluded 1 because any number can be divided by1. The result may or may not have a remainder. In the latter case we say that the particular integer has the capability of evenly dividing the given number. This capability is called as the divisibility of that integer for the given number. For example, 154 can evenly be divided by 7 and we can say 7 hasthe divisibility for 154.
Sometimes we may need to know whether a given number is divisible by a particular integer before proceeding with the division. There are some tricks to find that and these tricks are called as divisibility rules. The rules are different for different integers from 2 to 10. The advantage of the rules of divisibility also includes that it gives a hint of what could be added to or subtracted from the original number. The rules for different integers for testing divisibility may be compiled as a divisibility rules chart for ready reference. In course of time the chart gets into our memory automatically.
Now let us see what are the divisibility rules for some integers. The rules can obviously be seen and can be remembered for divisibility of a number by 2, 5, and 10. All numbers with the last digit as an even number can be divided by 2. All numbers with the last digit as 5 or 0 are divisible by 5. If any number ends with 0 as the last digit, obviously that number is divisible by 10.
We need to do a bit of mental exercise to find if a number is divisible by other integers within 10. Add all the digits of the given number. If the sum is divisible by 3, then the number is divisible by 3. If the last two digits of a number is divisible by 4, so also is the number. For divisible by 6, check the number is divisible by 2 and 3 as explained. If both tests are positive, then the number is divisible by 6. Understanding Examples of Pythagorean Triples is always challenging for me but thanks to all math help websites to help me out.
For testing 7, double the number from the last digit and subtract that from the rest of the digits. If the difference is divisible by 7, then the given number is also. For large numbers, you have to repeat the procedure.For dividing by 8, you need to work out if the last three digits are divisible by 8. If yes, then the number is divisible by 8. For divisibility of 9, the method is same as that of 3, excepting that the sum must be divisible by 9 indtead of 3.
Sometimes we may need to know whether a given number is divisible by a particular integer before proceeding with the division. There are some tricks to find that and these tricks are called as divisibility rules. The rules are different for different integers from 2 to 10. The advantage of the rules of divisibility also includes that it gives a hint of what could be added to or subtracted from the original number. The rules for different integers for testing divisibility may be compiled as a divisibility rules chart for ready reference. In course of time the chart gets into our memory automatically.
Now let us see what are the divisibility rules for some integers. The rules can obviously be seen and can be remembered for divisibility of a number by 2, 5, and 10. All numbers with the last digit as an even number can be divided by 2. All numbers with the last digit as 5 or 0 are divisible by 5. If any number ends with 0 as the last digit, obviously that number is divisible by 10.
We need to do a bit of mental exercise to find if a number is divisible by other integers within 10. Add all the digits of the given number. If the sum is divisible by 3, then the number is divisible by 3. If the last two digits of a number is divisible by 4, so also is the number. For divisible by 6, check the number is divisible by 2 and 3 as explained. If both tests are positive, then the number is divisible by 6. Understanding Examples of Pythagorean Triples is always challenging for me but thanks to all math help websites to help me out.
For testing 7, double the number from the last digit and subtract that from the rest of the digits. If the difference is divisible by 7, then the given number is also. For large numbers, you have to repeat the procedure.For dividing by 8, you need to work out if the last three digits are divisible by 8. If yes, then the number is divisible by 8. For divisibility of 9, the method is same as that of 3, excepting that the sum must be divisible by 9 indtead of 3.
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