有什么不懂的数学题可以跟贴

儿教 · 发表于 2006-4-25 12:29:01

北方天空+2006-04-23 15:02-->引用:北方天空 @ 2006-04-23 15:02 99999x99999=99999x(100000-1)=9999900000-99999=9999800001这样算出来是不是更快一点？

呵呵仁者见仁99999*99999=(100000-1)*(100000-1)=10000000000-200000+1呵呵

goodmov · 发表于 2006-4-28 22:38:46

得,是微积分的题 h=(80-a*a)/4a求v=a*a*h=20a-a*a*a/4 最大值求导 20-3a*a/4=0a*a=80/3h*h=20/3

sxz22 · 发表于 2006-5-1 10:54:37

请帮忙看看！谢谢！魔术师拿出一张写有１—１６的数字图。他说：“这是一张神奇的数字图。”　　众人问：“有什么神奇呀？” “你只要在心里默记表上的任何一个数字，”说着魔术师拿出一根特制的小棒，“我只要用这根魔棒在各个数字上点点敲敲，就知道你默记的是哪个数字了。”　　“要是这样，就真的神奇了！”众人兴致倍增。 芳芳说：“我已经记住了一个数，让你的魔棒点点敲敲吧！”<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">“<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">但是，我还有一个要求。<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">”<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">魔术师说，<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">“<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">当我的魔棒点到一个数时，你就在自己默记的数上加上１，我再点一个，你就再加上１<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">……<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">当你数到２０时，就说声<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">‘<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">停<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">’<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">。这时我的

儿教 · 发表于 2006-5-3 12:40:22

[quote]sxz22+2006-05-01 10:54-->引用:sxz22 @ 2006-05-01 10:54 请帮忙看看！谢谢！魔术师拿出一张写有１—１６的数字图。他说：“这是一张神奇的数字图。”　　众人问：“有什么神奇呀？” “你只要在心里默记表上的任何一个数字，”说着魔术师拿出一根特制的小棒，“我只要用这根魔棒在各个数字上点点敲敲，就知道你默记的是哪个数字了。”　　“要是这样，就真的神奇了！”众人兴致倍增。 芳芳说：“我已经记住了一个数，让你的魔棒点点敲敲吧！”<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">“<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">但是，我还有一个要求。<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">”<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">魔术师说，<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">“<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">当我的魔棒点到一个数时，你就在自己默记的数上加上１，我再点一个，你就再加上１<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">……<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">当你数到２０时，就说声<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">‘<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-bidi-font-family: 'Times New Roman'" twffan="done">停<span lang="EN-US" style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA" twffan="done">’<span style="FONT-SIZE: 9pt; COLOR: black; FONT-FAMILY: 宋体; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-ascii-font-f

goodmov · 发表于 2006-5-6 22:03:37

魔术师的顺序是：随便一个数，随便一个数2，随便一个数3，16，15，14，13，。。。。3，2，1 原因如下：第四下，16＋4＝20第五下，15＋5＝20 .......

雷彬妈 · 发表于 2006-5-8 10:48:01

看到你们，太高兴了，大家的见解实在太高了，佩服佩服！我女儿上一年级了，对数学实在是不感冒，连的她数学老师她都不喜欢，我也整天为了她了数学作业头痛，这几天学元、角、分，教的我头都大了，她也没学会，什么方法都试了，其它计算题、应用题还算可以、请大家帮忙指点指点、谢谢！

zhuxiaomang · 发表于 2006-5-10 09:39:43

我女儿也一年级，要教她元角分，我觉得最实在的方法就是让他用钱去买东西，算账吧！不知道对你女儿适用不了！

随地春风 · 发表于 2006-5-13 13:02:48

求助：一个礼堂有2006盏灯。要把2，3，5的倍数的灯打开，问打开多少盏？

随地春风 · 发表于 2006-5-13 13:13:58

求助：一个礼堂有2006盏灯，每盏有开关，从1，2，3，，，，，2006一次编号。把2，3，5的倍数的灯打开，问开了多少盏灯？

儿教 · 发表于 2006-5-19 10:14:28

随地春风+2006-05-13 13:02-->引用:随地春风 @ 2006-05-13 13:02 求助：一个礼堂有2006盏灯。要把2，3，5的倍数的灯打开，问打开多少盏？

是把2和3和5 的共同的倍数???？同时是2，3，5的倍数，那必然是2*3*5=30的倍数。那就有30，60，90。。。。。1980最大，，，，，那么他们之间的个数是（1980—30）/30+1=67个还是2的倍数的灯和3的倍数的灯和5的倍数的灯呢？这个就有蛮多的，，先算2的倍数，2006/2=10033的倍数：3。6。9。。。。。。。2004 （2004-3）/3+1=668再算5的倍数：5，10，15。。。。。。2005 （2005-5）/5+1=401即他们的和为1003+401+668-67=

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