document.write( "Question 507457: Round off the numbers to 1 significant digit and then estimate the value of the following expression without using a calculator. Show your work, writing your answer in scientific notation.\r
\n" ); document.write( "\n" ); document.write( "(287,900,001,000)*(168,000)=a*10^k \r
\n" ); document.write( "\n" ); document.write( "where a=___ and k=___ \n" ); document.write( "
Algebra.Com's Answer #340467 by Edwin McCravy(20056)\"\" \"About 
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Round off the numbers to 1 significant digit and then estimate the value of the following expression without using a calculator. Show your work, writing your answer in scientific notation.
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document.write( "(287,900,001,000)*(168,000)=a*10^k \r\n" );
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document.write( "where a=___ and k=___\r\n" );
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document.write( "You round 287,900,001,000 to 300,000,000,000 which is 3×1011\r\n" );
document.write( "You round 168,000 to 200,000 which is 2×105\r\n" );
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document.write( "So you have to multiply 3×1011 by 2×105\r\n" );
document.write( "so you multiply the 3 by the 2 getting 6 and add the exponents of 10, \r\n" );
document.write( "getting 11+5 or 16.  So a = 6 and k = 16. \r\n" );
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document.write( "So you get 6×1016.\r\n" );
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document.write( "Edwin
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