Comments on: Techniques for adding the numbers 1 to 100 http://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/ Learning shouldn't hurt. Let's share the insights that made difficult ideas click. Fri, 25 Jul 2008 14:15:40 +0000 http://wordpress.org/?v=2.0 by: Explained: Sum of all numbers « Lost in Thoughts… http://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/#comment-144607 Fri, 04 Apr 2008 03:25:58 +0000 http://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/#comment-144607 [...] I just read an entry, which explains the following formula, not in 2 but 4 different ways. Sum from 1 to n =  [...] […] I just read an entry, which explains the following formula, not in 2 but 4 different ways. Sum from 1 to n =  […]

]]> by: The blog of whall » Stuff you don’t want to MISC, #37 http://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/#comment-139911 Mon, 10 Mar 2008 00:00:10 +0000 http://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/#comment-139911 [...] FYI: The trick is to think - hmm, take one number from the top and one number from the bottom - ie, 99+1=100.  Then take the next one from top and bottom because 98+2=100 also.  97+3=100, 96+4=100, etc.  So now you’ve gotten rid of 49 of them (all the way to 49+51=100), so you have 4900, then you just have the 50 and the 100 left over, so the answer is 5050.  I even looked online to see if this shortcut was there, but this one guy went all way too complex with his “possible solutions.” [...] […] FYI: The trick is to think - hmm, take one number from the top and one number from the bottom - ie, 99+1=100.  Then take the next one from top and bottom because 98+2=100 also.  97+3=100, 96+4=100, etc.  So now you’ve gotten rid of 49 of them (all the way to 49+51=100), so you have 4900, then you just have the 50 and the 100 left over, so the answer is 5050.  I even looked online to see if this shortcut was there, but this one guy went all way too complex with his “possible solutions.” […]

]]> by: Kalid http://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/#comment-137943 Sat, 01 Mar 2008 01:27:08 +0000 http://betterexplained.com/articles/techniques-for-adding-the-numbers-1-to-100/#comment-137943 Hi Zac, thanks for the awesome comment! That's a cool way to look at it, I like the approach of making a full box (n^2) and then taking pieces away. Yep, it goes to show that there are so many ways of looking at a single formula :). Hi Zac, thanks for the awesome comment! That’s a cool way to look at it, I like the approach of making a full box (n^2) and then taking pieces away.

Yep, it goes to show that there are so many ways of looking at a single formula :) .

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