document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=564340>Question 564340</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need to know the formula for adding whole numbers (1+2+3+4...) to get a sum over 1000.  I know the answer is 45 but I need the formula to figure it out.\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #365337 by </B><A HREF=/tutors/aboutme.mpl?userid=ad_alta><B>ad_alta(240)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ad_alta><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=ad_alta><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=365337\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I should probably let you discover it on your own (its more fun that way), but the answer is n(n+1)/2. Since we're talking about n=1000, 1000(1001)/2=500,500. \r<BR>\n" );
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document.write( "Or in your case, (1+2+3+4+5+6+7+8+9)=(9)(10)/2=45. </SPAN>\n" );
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