http://betterexplained.com/articles/mental-math-shortcuts/ Learning shouldn't hurt. Let's share the insights that made difficult ideas click. Fri, 20 Nov 2009 14:09:06 -0800 http://wordpress.org/?v=2.8.4 hourly 1 http://betterexplained.com/articles/mental-math-shortcuts/#comment-257810 Srivarshani Thu, 15 Oct 2009 17:55:38 +0000 http://betterexplained.com/articles/mental-math-shortcuts/#comment-257810 Hai Ido not about shortcuts But there are formulae to find the sum OR term in arithmetic progression First term=a difference=d n=No of terms l=last term Then n=((l-a)/d)+One t(n)=a+(n-one)d ,sum(n)=n/2(2a+(n-one)d)OR s(n)=n/2(a+l) For odd nos The sum is n to the power 2 (to Leilani) Hai Ido not about shortcuts But there are formulae to find the sum OR term in arithmetic progression First term=a difference=d n=No of terms l=last term Then n=((l-a)/d)+One
t(n)=a+(n-one)d ,sum(n)=n/2(2a+(n-one)d)OR
s(n)=n/2(a+l) For odd nos The sum is n to the power 2 (to Leilani)

]]> http://betterexplained.com/articles/mental-math-shortcuts/#comment-249967 The Count Fri, 14 Aug 2009 18:19:30 +0000 http://betterexplained.com/articles/mental-math-shortcuts/#comment-249967 Nice ones. I posted my own multiplication shortcuts on Discrete Ideas. Nice ones. I posted my own multiplication shortcuts on Discrete Ideas.

]]> http://betterexplained.com/articles/mental-math-shortcuts/#comment-249195 aviral tiwari Fri, 24 Jul 2009 10:00:25 +0000 http://betterexplained.com/articles/mental-math-shortcuts/#comment-249195 to multiply any three number by 11just dooooooo this thing e.g 453 last no 3 will come in last then 2and3 no is 5 3 we will add=8 now.we will add 1and2 no is 4 5 we will add=9 now right the first no 4 ans ==========4983 (453*11=4983)magic ) Aviral Tiwari to multiply any three number by 11just dooooooo this thing e.g
453
last no 3 will come in last then
2and3 no is 5 3 we will add=8
now.we will add 1and2 no is 4 5 we will add=9
now right the first no 4
ans ==========4983
(453*11=4983)magic )
Aviral Tiwari

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