A 24 hour clock displays digits whose sum total equals the number of led's used to display them 94 times a day. A 12 hour clock displays them 108 times a day.
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They are called the digital roots.
Divisibility if a number by 3 is not determined by its last digits: instead it is determined by the number's digital root.You get the digital root of a number by adding together all its digits. If the answer is a big number, then find the digital root of the answer. Keep going until you have a number that is smaller than 10. If this number is 3, 6 or 9 (all divisible by 3) then the original number is divisible by 3. And it not, it is not.
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"Digital" is related to the word "digit", in its sense of a number. In a device like a computer, all of the information is translated to binary numbers. Sounds and photographs are reduced to numbers, and are referred to as "digital sounds" or "digital numbers". A digital camera is a camera which records images in this way. In terms of a display, a "digital display" on a clock or speedometer or such similar device displays numbers, digits, to convey the information. An "analog display" on the other hand, displays the information on a dial.
If the sum of the digits of a given number equals nine or a multiple of nine, nine is a factor of that number.
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It is another whole number.
They are called the digital roots.
There are several hundred of them. One example, the smallest, is 1039
It reduces the number of digits after the decimal point in the display, rounding the number as appropriate.
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Divisibility if a number by 3 is not determined by its last digits: instead it is determined by the number's digital root.You get the digital root of a number by adding together all its digits. If the answer is a big number, then find the digital root of the answer. Keep going until you have a number that is smaller than 10. If this number is 3, 6 or 9 (all divisible by 3) then the original number is divisible by 3. And it not, it is not.
As of January 25, 2014, the largest known prime number was calculated to be 257,885,161 − 1; a number containing 17,425,170 digits. This is, of course, too large to display.
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There an infinity of such numbers. One test for divisibility by 9 depends on the digital root. The digital root of any number is the sum of all its digits. If the digital root of a number (or the digital root of its digital root) is divisible by 9 then the original number is, and if the DR is not then the original number is not.