DIVISIBLTY

موضوع: DIVISIBLTY الجمعة أبريل 10, 2009 12:23 pm

Numbers are divisible by two if the ones digit is evenly divisible by two. This ‎means that even numbers are divisible by two.‎

Numbers are divisible by three if the sum of all the individual digits is evenly ‎divisible by three. For example, the sum of the digits for the number 3627 ‎is 18, which is evenly divisible by three so the number 3627 is evenly ‎divisible by three.‎

Whole numbers are divisible by four if the number formed by the last two ‎individual digits is evenly divisible by four. For example, the number formed ‎by the last two digits of the number 3628 is 28, which is evenly divisible by ‎four so the number 3628 is evenly divisible by four.‎

Numbers are evenly divisible by 5 if the last digit of the number is 0 or 5.‎

Numbers are evenly divisible by six if they are evenly divisible by both two ‎And 3. Even numbers are always evenly divisible by two. Numbers are evenly ‎divisible by three if the sum of all the individual digits is evenly divisible by ‎three. For example, the sum of the digits for the number 3627 is 18, which ‎is evenly divisible by 3 but 3627 is an odd number so the number 3627 is not ‎evenly divisible by six.‎

To determine if a number is divisible by seven, take the last digit off the ‎number, double it and subtract the doubled number from the remaining ‎number. If the result is evenly divisible by seven (e.g. 14, 7, 0, -7, etc.), then ‎the number is divisible by seven. This may need to be repeated several ‎times.‎
Example: Is 3101 evenly divisible by seven? ‎

‎ 310 - Take off the last digit of the number, which was 1‎
‎ -2 - double the removed digit and subtract it‎
‎ 308 - Repeat the process by taking off the eight‎
‎-16 - And doubling it to get 16 which is subtracted‎
‎ 14 - The result is 14 which is a multiple of 7 ‎

Numbers are divisible by eight if the number formed by the last three ‎individual digits is evenly divisible by eight. For example, the last three ‎digits of the number 3624 is 624, which is evenly divisible by eight so 3624 ‎is evenly divisible by 8.‎

A number is divisible by 10 only if the last digit is a zero. Numbers are ‎divisible by nine if the sum of all the individual digits is evenly divisible by ‎nine. For example, the last sum of the digits of the number 3627 is 18, which ‎is evenly divisible by nine so 3627 is evenly divisible by nine.‎