document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=467012>Question 467012</A>: <I><SPAN STYLE=\"word-break: break-all;\"> sum of 1+2+3+...+81 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #320295 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=320295\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You can add them with a calculator, might take awhile.<BR>\n" );
document.write( "You can have Excel do it, quicker and less chance of error.<BR>\n" );
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document.write( "There are 81 elements.<BR>\n" );
document.write( "If you make pairs with the outside elements, 1 & 81, 2 & 80, etc, the pairs add to 82.<BR>\n" );
document.write( "You'll get 40 pairs and the middle number left over.  The middle number is 41<BR>\n" );
document.write( "40*82 + 41 = 3321<BR>\n" );
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