document.write( "Question 164864: What is the ones's digit of 8^1007?\r
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Algebra.Com's Answer #121489 by Alan3354(69443)![]() ![]() You can put this solution on YOUR website! What is the ones's digit of 8^1007? \n" ); document.write( "---------------- \n" ); document.write( "The one's digit of any even number (except zero) to a power of a multiple of 4, is 6. That is, 8^(4*n) --> xxxxxxxx6 (n is an integer). \n" ); document.write( "1007 = 4*251 + 3. \n" ); document.write( "8^1007 = (8^1004)*(8^3) \n" ); document.write( "8^3 = 512. \n" ); document.write( "Multiplying an even number by 6 does not change the one's digit. \n" ); document.write( "So, the one's digit of 8^1007 is 2. \n" ); document.write( "-------------------------- \n" ); document.write( "PS All calculators have a limit on their resolution, and they can only generate results to a certain number of significant figures. This does not mean that the digits to the right are actually zeroes, but only that the calculator has a limited ability to generate and display a limited number of digits, and it fills in the space with zeroes. \n" ); document.write( " |