You can put this solution on YOUR website! What is the sum of 1 up to 100
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List the numbers: 1,2,3,4,....98,99,100
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Notice that
1+100 = 101
2+99 = 101
3+97 = 101
........
50+51 = 101
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Sum = 50(101) = 5050
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Cheers,
Stan H.