1、積的變化規(guī)律,合作伙伴：劉智明,62,620,6200,104,54,12,120,80,40,1200,20,204,（1）,（2）,比比誰(shuí)最快,一、復(fù)習(xí)導(dǎo)入,觀察下面兩組題，說(shuō)一說(shuō)你發(fā)現(xiàn)了什么？,二、探究新知,觀察下面兩組題，說(shuō)一說(shuō)你發(fā)現(xiàn)了什么。,二、探究新知,觀察下面兩組題，說(shuō)一說(shuō)你發(fā)現(xiàn)了什么。,二、探究新知,62,620,6200,120,1200,（1）,12,104,54,80,40,20,204,（2）,第（1）組題中，第2題同第1題比，因數(shù) 是怎樣變化的？積是怎樣變化的？,一個(gè)因數(shù)不變，另一個(gè) 因數(shù)乘10，積也乘10。,二、探究新知,第（1）組題中，第3題同第1題比，因數(shù) 是怎

2、樣變化的？積是怎樣變化的？,一個(gè)因數(shù)不變，另一個(gè)因數(shù) 乘100，積也乘100。,62,620,6200,120,1200,（1）,12,104,54,80,40,20,204,（2）,二、探究新知,觀察第（2）組題，因數(shù)是怎樣 變化的？積是怎樣變化的？,62,620,6200,120,1200,（1）,12,104,54,80,40,20,204,（2）,二、探究新知,一個(gè)因數(shù)不變，另一個(gè)因數(shù)乘（或除以）幾（0除外），積也乘（或除以）幾。,二、探究新知,254100 25041000 如果從下往上觀察，第二 個(gè)因數(shù)沒(méi)變，第一個(gè)因數(shù) 除以10，積也除以10。,我是這么舉例的： 254100 25

3、041000 從上往下觀察，第二個(gè)因數(shù)沒(méi)變，第一個(gè)因數(shù)乘10，積也乘10。,能舉例說(shuō)明你發(fā)現(xiàn)的 規(guī)律嗎？,三、鞏固提升,1. 先算出每組題中第1題的積，再寫出下面 兩題的得數(shù)。,123,1203,12030,485,4850,48500,850,825,450,36,360,3600,240,2400,24000,400,200,200,三、鞏固提升,2、用積的變化規(guī)律填空。,1824,1812,186,432,216,108,四、拓展延伸,1、完成下列計(jì)算，并說(shuō)說(shuō)自己發(fā)現(xiàn)的規(guī)律。,1824,（182）（242）,（182）（242）,積不變的規(guī)律： 一個(gè)因數(shù)乘幾，另一個(gè)因數(shù)除以相同的數(shù)，積不

4、變。,這堂課，你有什么收獲？,1. CLICK TO EDIT TITLE STYLE,2. CLICK TO EDIT TITLE STYLE,3. CLICK TO EDIT TITLE STYLE,COMPANY LOGOTYPE INSERT,COPYRIGHT(C)2008 PPTKOREA CO.,LTD & DESIGN COMPANY,4. CLICK TO EDIT TITLE STYLE,Click To Edit Title Style,Click To Type Slide Title,Pictures speak 1,000 words! Design Inspira

5、tion Clarity & Impact Premium Design Subtle Touch Visual Appealing Stylish Design Simplicity & Beauty 3D Effect Stylish templates can be a valuable aid to creative professionals. Each work is featured with simplicity but supreme beauty.,Click To Type Slide Title,Click To Type Slide Title,Click To Ty

6、pe Slide Title,Click To Type Slide Title,Ready to Use Immense visual appeal Premade PowerPoint Templates, Professional quality templates in a couple of clicks away!,Click To Type Slide Title,Click To Type Slide Title,Click To Type Slide Title,Pictures speak 1,000 words! Catch The feel of Design in c

7、ontemporary colors and styles Creative Visual Aids! Feel the touch of Design on the cutting edge,Click To Type Slide Title,Click To Type Slide Title,Click To Type Slide Title,Click To Type Slide Title,Click To Type Slide Title,Click To Type Slide Title,Click To Type Slide Title,Click To Type Slide Title,Click To Type S