document.write( "Question 924190: if log0.5 = -0.3010, what is the mantissa of log0.5? \n" ); document.write( "
Algebra.Com's Answer #560681 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
if log0.5 = -0.3010, what is the mantissa of log0.5?
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document.write( "Wow!  Who is still doing work with logarithm tables?\r\n" );
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document.write( "Here is how it was done in the old days:\r\n" );
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document.write( "We added the equation to the equation 0 = 10.0000 - 10 which \r\n" );
document.write( "amounted to adding to zero: \r\n" );
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document.write( "        0 = 10.0000 - 10\r\n" );
document.write( "   log0.5 = -0.3010 \r\n" );
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document.write( "   log0.5 =  9.6990 - 10\r\n" );
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document.write( "So the mantissa is the decimal digits .6990.\r\n" );
document.write( "The characteristic is -1, since 0.5 = 5×10-1 the\r\n" );
document.write( "power of 10 in the scientific notation for the number.\r\n" );
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document.write( "We did this sort of thing 50+ years ago before electronic calculators\r\n" );
document.write( "were invented, back when there were no cell phones and the only\r\n" );
document.write( "computers were huge and had no video screens.  We used logarithm tables\r\n" );
document.write( "to multiply and divide in complicated calculations. I am shocked to \r\n" );
document.write( "see somebody still doing this today.  With modern calculators there \r\n" );
document.write( "is no need for this very ancient type of calculation. I would be \r\n" );
document.write( "interested to know who is still teaching this.  Is it a part of \r\n" );
document.write( "a mathematical history course?\r\n" );
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document.write( "Edwin
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