1、【2020新】北师大版六年级下册数学课件比例的应用课后课后作业作业探索探索新知新知1课堂探究点课堂探究点2课时流程课时流程课堂课堂小结小结当堂当堂检测检测探究点探究点 解比例的方法解比例的方法14个玩具汽车可以换多少本小人书?个玩具汽车可以换多少本小人书?1443.53.51035(本)(本)x假设假设14个玩具汽车可以换个玩具汽车可以换x本小人书,尝试用比例的本小人书,尝试用比例的方法解决问题。方法解决问题。14个玩具汽车可以换多少本小人书?个玩具汽车可以换多少本小人书?4:1014:x14:4x:10一辆小汽车换几本小人书一辆小汽车换几本小人书玩具汽车(小人书)间的倍数玩具汽车(小人书)间
2、的倍数解:解:4x140 x35 解:解:4x140 x35 答:答:14个玩具汽车可以换个玩具汽车可以换35本书。本书。假设假设14个玩具汽车可以换个玩具汽车可以换x本小人书,尝试用比例的方法本小人书,尝试用比例的方法解决问题。解决问题。14个玩具汽车可以换多少本小人书?个玩具汽车可以换多少本小人书?解:解:0.3x240.4x9.60.3 0.3x9.6x32 解:解:7x43.5x147 7x14x2 检验:检验:24:0.38032:0.480检验:检验:解下面的比例,与同伴交流。解下面的比例,与同伴交流。24 0.3x 0.4小试牛刀小试牛刀(源于(源于典中点典中点)1填空。填空。(
3、1)5个鸡蛋可以换个鸡蛋可以换4元,妈妈有元,妈妈有100个鸡蛋,可以换个鸡蛋,可以换()元。元。(2)12个桃可以换个桃可以换4个苹果,小猴有个苹果,小猴有30个苹果,可以个苹果,可以换换()个桃。个桃。80902写出比例,并求出未知数。写出比例,并求出未知数。3支钢笔可以换支钢笔可以换20个练习本,小玲用个练习本,小玲用120个练习本个练习本换了换了x支钢笔。支钢笔。320 x120 x183谁做得对,在括号里画谁做得对,在括号里画“”。4解比例。解比例。x452436 15x0.244 280.16525x 183.68x解:解:36x 1080 x 30解:解:0.2x 660 x 3
4、300 解:解:3.6x 144 x 40160.161254 5xx解:解:1.250.251.6x1.22575x解:解:0.25x 2 x8 解:解:75x 30 x 0.45解决问题。解决问题。(1)科技种植园所种的太空黄瓜和航豇科技种植园所种的太空黄瓜和航豇1号面积的比是号面积的比是53,航豇,航豇1号的种植面积是号的种植面积是45 m2,太空黄瓜的,太空黄瓜的种植面积是多少平方米?种植面积是多少平方米?解:设太空黄瓜的种植面积是解:设太空黄瓜的种植面积是x m2。53x45 x75答:太空黄瓜的种植面积是答:太空黄瓜的种植面积是75 m2。(2)某品牌手机生产厂设计制作了一个手机模
5、型,模型某品牌手机生产厂设计制作了一个手机模型,模型长与手机实际长度的比是长与手机实际长度的比是121。手机的实际长度。手机的实际长度是是15 cm,模型的长是多少米?,模型的长是多少米?解:设模型的长是解:设模型的长是x cm。121x15 x180180 cm1.8 m答:模型的长是答:模型的长是1.8 m。(3)甜甜在教学楼前测得一根标杆的高度与影子长度的甜甜在教学楼前测得一根标杆的高度与影子长度的比是比是43。已知教学楼的实际高度是。已知教学楼的实际高度是14 m,教学,教学楼的影子长多少米?楼的影子长多少米?解:设教学楼的影子长解:设教学楼的影子长x m。4314x x10.5答:教
6、学楼的影子长答:教学楼的影子长10.5 m。归纳总结:归纳总结:(讲解源于(讲解源于典中点典中点)解比例的方法:解比例的方法:(1)根据比例的基本性质把比例式转化成乘根据比例的基本性质把比例式转化成乘法等式,即方程;法等式,即方程;(2)解方程求出未知项的值。解方程求出未知项的值。小试牛刀小试牛刀(教材(教材P20练一练)练一练)1.作业本上的作业本上的6个小星星可以换个小星星可以换2面小红旗。淘气的作业本面小红旗。淘气的作业本 上已经有了上已经有了15个小星星。个小星星。(1)15个小星星可以换多少面小红旗?说说你的想法。个小星星可以换多少面小红旗?说说你的想法。1.(2)假设)假设15个小
7、星星可以换个小星星可以换x面小红旗,你能列面小红旗,你能列比例并解决问题吗?比例并解决问题吗?6:215:x解:解:6x30 x5 15个小星星可以换个小星星可以换5面小红旗。想法略。面小红旗。想法略。2.写出比例,并求出未知数。写出比例,并求出未知数。1 4x 84解:解:4x84 x21 4 10 x 250解:解:10 x1000 x1003.解方程。解方程。4 9x 3.6解:解:9x43.6 x1.6 解:解:27x918 x611146121 18xx 解:解:4.淘气和笑笑收集的邮票张数的比是淘气和笑笑收集的邮票张数的比是3:5。淘气收集了。淘气收集了36张张 邮票,笑笑收集的邮
8、票有多少张?邮票,笑笑收集的邮票有多少张?解:设笑笑收集的邮票有解:设笑笑收集的邮票有x张。张。3 536 x 3x180 x60答:笑笑收集的邮票有答:笑笑收集的邮票有60张。张。5.广州塔高广州塔高600m,是目前世界第一高的,是目前世界第一高的 电视塔。星星公司设计制作了这座电视电视塔。星星公司设计制作了这座电视 塔的模型,模型的高度与实际高度的比塔的模型,模型的高度与实际高度的比 是是1:300。模型的高度是多少米?。模型的高度是多少米?解:设模型的高度是解:设模型的高度是x m。1 300 x 600 300 x600 x2答:模型的高度是答:模型的高度是2 m。易错辨析易错辨析6下
9、面解比例的方法对吗?若不对,请改正。下面解比例的方法对吗?若不对,请改正。12 x2 1.8 解:解:1.8x 122 ()12 21.8403xx 改正:改正:12x21.8 解:解:2x 121.8 x 10.8易错点:解比例时应利用内项积等于外项积。易错点:解比例时应利用内项积等于外项积。版权申明本文部分内容,包括文字、图片、以及设计等在网上搜集整理.版权为个人所有This article includes some parts,including text,pictures,and design.Copyright is personal ownership.用户可将本文地内容或服务用
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17、is article,and shall bear legal liability such as copyright.版权申明本文部分内容,包括文字、图片、以及设计等在网上搜集整理.版权为个人所有This article includes some parts,including text,pictures,and design.Copyright is personal ownership.用户可将本文地内容或服务用于个人学习、研究或欣赏,以及其他非商业性或非盈利性用途,但同时应遵守著作权法及其他相关法律地规定,不得侵犯本网站及相关权利人地合法权利.除此以外,将本文任何内容或服务用于其他用
18、途时,须征得本人及相关权利人地书面许可,并支付报酬.Users may use the contents or services of this article for personal study,research or appreciation,and other non-commercial or non-profit purposes,but at the same time,they shall abide by the provisions of copyright law and other relevant laws,and shall not infringe upon th
19、e legitimate rights of this website and its relevant obligees.In addition,when any content or service of this article is used for other purposes,written permission and remuneration shall be obtained from the person concerned and the relevant obligee.转载或引用本文内容必须是以新闻性或资料性公共免费信息为使用目地地合理、善意引用,不得对本文内容原意进
20、行曲解、修改,并自负版权等法律责任.Reproduction or quotation of the content of this article must be reasonable and good-faith citation for the use of news or informative public free information.It shall not misinterpret or modify the original intention of the content of this article,and shall bear legal liability su
21、ch as copyright.版权申明本文部分内容,包括文字、图片、以及设计等在网上搜集整理.版权为个人所有This article includes some parts,including text,pictures,and design.Copyright is personal ownership.用户可将本文地内容或服务用于个人学习、研究或欣赏,以及其他非商业性或非盈利性用途,但同时应遵守著作权法及其他相关法律地规定,不得侵犯本网站及相关权利人地合法权利.除此以外,将本文任何内容或服务用于其他用途时,须征得本人及相关权利人地书面许可,并支付报酬.Users may use the
22、contents or services of this article for personal study,research or appreciation,and other non-commercial or non-profit purposes,but at the same time,they shall abide by the provisions of copyright law and other relevant laws,and shall not infringe upon the legitimate rights of this website and its
23、relevant obligees.In addition,when any content or service of this article is used for other purposes,written permission and remuneration shall be obtained from the person concerned and the relevant obligee.转载或引用本文内容必须是以新闻性或资料性公共免费信息为使用目地地合理、善意引用,不得对本文内容原意进行曲解、修改,并自负版权等法律责任.Reproduction or quotation
24、of the content of this article must be reasonable and good-faith citation for the use of news or informative public free information.It shall not misinterpret or modify the original intention of the content of this article,and shall bear legal liability such as copyright.版权申明本文部分内容,包括文字、图片、以及设计等在网上搜
25、集整理.版权为个人所有This article includes some parts,including text,pictures,and design.Copyright is personal ownership.用户可将本文地内容或服务用于个人学习、研究或欣赏,以及其他非商业性或非盈利性用途,但同时应遵守著作权法及其他相关法律地规定,不得侵犯本网站及相关权利人地合法权利.除此以外,将本文任何内容或服务用于其他用途时,须征得本人及相关权利人地书面许可,并支付报酬.Users may use the contents or services of this article for per
26、sonal study,research or appreciation,and other non-commercial or non-profit purposes,but at the same time,they shall abide by the provisions of copyright law and other relevant laws,and shall not infringe upon the legitimate rights of this website and its relevant obligees.In addition,when any conte
27、nt or service of this article is used for other purposes,written permission and remuneration shall be obtained from the person concerned and the relevant obligee.转载或引用本文内容必须是以新闻性或资料性公共免费信息为使用目地地合理、善意引用,不得对本文内容原意进行曲解、修改,并自负版权等法律责任.Reproduction or quotation of the content of this article must be reaso
28、nable and good-faith citation for the use of news or informative public free information.It shall not misinterpret or modify the original intention of the content of this article,and shall bear legal liability such as copyright.版权申明本文部分内容,包括文字、图片、以及设计等在网上搜集整理.版权为个人所有This article includes some parts,
29、including text,pictures,and design.Copyright is personal ownership.用户可将本文地内容或服务用于个人学习、研究或欣赏,以及其他非商业性或非盈利性用途,但同时应遵守著作权法及其他相关法律地规定,不得侵犯本网站及相关权利人地合法权利.除此以外,将本文任何内容或服务用于其他用途时,须征得本人及相关权利人地书面许可,并支付报酬.Users may use the contents or services of this article for personal study,research or appreciation,and oth
30、er non-commercial or non-profit purposes,but at the same time,they shall abide by the provisions of copyright law and other relevant laws,and shall not infringe upon the legitimate rights of this website and its relevant obligees.In addition,when any content or service of this article is used for ot
31、her purposes,written permission and remuneration shall be obtained from the person concerned and the relevant obligee.转载或引用本文内容必须是以新闻性或资料性公共免费信息为使用目地地合理、善意引用,不得对本文内容原意进行曲解、修改,并自负版权等法律责任.Reproduction or quotation of the content of this article must be reasonable and good-faith citation for the use of
32、 news or informative public free information.It shall not misinterpret or modify the original intention of the content of this article,and shall bear legal liability such as copyright.版权申明本文部分内容,包括文字、图片、以及设计等在网上搜集整理.版权为个人所有This article includes some parts,including text,pictures,and design.Copyright
33、 is personal ownership.用户可将本文地内容或服务用于个人学习、研究或欣赏,以及其他非商业性或非盈利性用途,但同时应遵守著作权法及其他相关法律地规定,不得侵犯本网站及相关权利人地合法权利.除此以外,将本文任何内容或服务用于其他用途时,须征得本人及相关权利人地书面许可,并支付报酬.Users may use the contents or services of this article for personal study,research or appreciation,and other non-commercial or non-profit purposes,but
34、 at the same time,they shall abide by the provisions of copyright law and other relevant laws,and shall not infringe upon the legitimate rights of this website and its relevant obligees.In addition,when any content or service of this article is used for other purposes,written permission and remunera
35、tion shall be obtained from the person concerned and the relevant obligee.转载或引用本文内容必须是以新闻性或资料性公共免费信息为使用目地地合理、善意引用,不得对本文内容原意进行曲解、修改,并自负版权等法律责任.Reproduction or quotation of the content of this article must be reasonable and good-faith citation for the use of news or informative public free information.It shall not misinterpret or modify the original intention of the content of this article,and shall bear legal liability such as copyright.