math quiz: 1/2 + 1/(2*3) + 1/(3*4) + 1/(4*5) ... 1/(1995*1996) = ?

math quiz: 1/2 + 1/(23) + 1/(34) + 1/(45) ... 1/(19951996) = ?

送交者: steven 于 2009-01-30, 16:36:33:

This is one of my son's homework problem, and he is a 4th grader. see how fast can you guys come up with the solution.

The result should be 1995/1996 (无内容) - chinada (0 bytes) 2009-01-30, 16:45:39 (296469)
- Please explain :) thank you!!! - hootoo (110 bytes) 2009-01-30, 18:41:58 (296484)
  - 1/(n*(n+1))=(n+1-n)/(n*(n+1))=1/n - 1/(n+1) - 插一腿 (1 bytes) 2009-01-30, 20:47:47 (296493)
    - 1/2 + 1/2 -1/1996 = 1995/1996 (无内容) - 插一腿 (0 bytes) 2009-01-30, 20:50:30 (296494)
      - 赞一个！不愧是学数学出身，宝腿未老！ (无内容) - 找老婆专用ID (0 bytes) 2009-01-30, 21:33:10 (296501)
- no. (无内容) - steven (0 bytes) 2009-01-30, 16:48:48 (296472)
  - I meant yes, sorry. (无内容) - steven (0 bytes) 2009-01-30, 16:49:23 (296473)
    - Yes 和 No 都能搞混，哲学家！ (无内容) - 008 (0 bytes) 2009-01-30, 22:42:56 (296503)
      - 难得糊涂。 (无内容) - steven (0 bytes) 2009-01-31, 00:46:44 (296510)
N年都不玩数学抢答题了,脑袋不转了,弃权,等着开糊 (无内容) - blackbox (0 bytes) 2009-01-30, 16:43:08 (296467)
- test (无内容) - laoliu (0 bytes) 2009-02-01, 06:16:49 (296658)