document.write( "Question 643622: find the sum of the whole number from 1 to 9999 \n" ); document.write( "

Algebra.Com's Answer #404554 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
First do a shorter sequence to get the
\n" ); document.write( "right method. First find the sum of
\n" ); document.write( "0 to 10
\n" ); document.write( " $\"+0+%2B+1+%2B+2+%2B+3+%2B+4+%2B+5+%2B+6+%2B+7+%2B+8+%2B+9+%2B+10+=+55+\"$
\n" ); document.write( "( I did it on my calculator )
\n" ); document.write( "This is $\"+%2810%2F2%29%2A%28+10+%2B+1+%29+\"$
\n" ); document.write( "How about
\n" ); document.write( " $\"+0+%2B+1+%2B+2+%2B+3+%2B+4+%2B+5+%2B+6+%2B+7+%2B+8+%2B+9+%2B+10+%2B+11+%2B+12+%2B+13+=+91+\"$
\n" ); document.write( "This is $\"+%2813%2F2%29%2A%28+13+%2B+1+%29+\"$
\n" ); document.write( "----------------------
\n" ); document.write( "So, the formula is:
\n" ); document.write( "The sum of the numbers from 1 to n =
\n" ); document.write( " $\"+%28n%2F2%29%2A%28+n+%2B+1+%29+\"$
\n" ); document.write( "---------------
\n" ); document.write( " $\"+n+=+9999+\"$
\n" ); document.write( " $\"+%28+9999%2F2+%29%2A%28+9999+%2B+1+%29+=+4999.5%2A10000+\"$
\n" ); document.write( " $\"+4999.5%2A10000+=+49995000+\"$ \n" ); document.write( "

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