1+1000 + 2+999 + 3+998 + É + 500+501 =
500*1001 =
500500
GaussÕ 3rd Grade Technique
Compute 1+2+3+ É + 1000:
In general, 1+2+3+É+n = n*(n+1)/2
(Òarithmetic Ó series vs. ÒgeometricÓ series)
