有理數(shù)知識點總結(jié)與典型例題人教版初中數(shù)學(xué)

1、襄陽五中實驗中學(xué)我的新浪博客：:blog..cn5942jiaoyu有理數(shù)知識點目錄有理數(shù)知識點目錄一、正數(shù)和負數(shù)一、正數(shù)和負數(shù)................................................................................................................................2考向1：正數(shù)和負數(shù)的概念...............

2、......................................................................................2考向2：正數(shù)和負數(shù)的相反意義.............................................................................................2二、有理數(shù)二、有理數(shù)...............

3、.........................................................................................................................3考向3：有理數(shù)的分類........................................................................................

4、.....................3三、數(shù)軸三、數(shù)軸............................................................................................................................................4考向4：數(shù)軸的定義........................................

5、.........................................................................5考向5：利用數(shù)軸比較兩數(shù)的大小.........................................................................................5四、相反數(shù)四、相反數(shù)...............................

6、.........................................................................................................6考向6：相反數(shù)...........................................................................................................

7、..............6五、絕對值五、絕對值........................................................................................................................................6考向7：求一個數(shù)的絕對值..............................................

8、.......................................................7考向8：有理數(shù)的大小比較.....................................................................................................7六、有理數(shù)的加法六、有理數(shù)的加法..................................

9、..........................................................................................9考向9：有理數(shù)的加法.............................................................................................................9七、有理數(shù)的減法七

10、、有理數(shù)的減法..........................................................................................................................10考向10：有理數(shù)的減法..............................................................................

11、...........................10八、有理數(shù)的乘法八、有理數(shù)的乘法..........................................................................................................................12考向11：有理數(shù)的乘法........................................

12、.................................................................12九、有理數(shù)的除法九、有理數(shù)的除法..........................................................................................................................14考向12：有理數(shù)的除法..

13、.......................................................................................................14十、乘方十、乘方...........................................................................................................

14、...............................16考向13：乘方的運算.............................................................................................................16十一、有理數(shù)的混合運算十一、有理數(shù)的混合運算............................................

15、..................................................................18十二、科學(xué)計數(shù)法十二、科學(xué)計數(shù)法..........................................................................................................................18考向14：科學(xué)計數(shù)法..

16、...........................................................................................................18十三、近似數(shù)十三、近似數(shù)...................................................................................................

17、...............................19考向15：近似數(shù).....................................................................................................................19參考答案：參考答案：..................................................

18、....................................................................................21襄陽五中實驗中學(xué)我的新浪博客：:blog..cn5942jiaoyuC5表示向西運動了5米D向西運動5米也可以記作向西運動5米二、有理數(shù)二、有理數(shù)1、有理數(shù)的概念：⑴整數(shù)和分?jǐn)?shù)統(tǒng)稱為有理數(shù)；⑵正整數(shù)、0、負整數(shù)統(tǒng)稱為整數(shù)（0和正整數(shù)統(tǒng)稱為自然數(shù)）；⑶正分?jǐn)?shù)和負分?jǐn)?shù)統(tǒng)稱

19、為分?jǐn)?shù).說明：①由于整數(shù)可以看成是分母為1的分?jǐn)?shù)，所以有理數(shù)可以用（是整數(shù)，pqqp）表示；②只有能化成分?jǐn)?shù)的數(shù)才是有理數(shù)；③π是無限不循環(huán)小數(shù)，不能0?q寫成分?jǐn)?shù)形式，不是有理數(shù)；④有限小數(shù)和無限循環(huán)小數(shù)都可化成分?jǐn)?shù)，都是有理數(shù)。2、有理數(shù)的分類：說明：①有理數(shù)最終可分為5類：正整數(shù)、正分?jǐn)?shù)、零、負整數(shù)、負分?jǐn)?shù)；②其他常見分類方法：例如：非正數(shù)、非負整數(shù)、非負有理數(shù)……非正數(shù)：（不是正數(shù)）=負數(shù)和零非負整數(shù)：（不是負的整數(shù)）=正整數(shù)和

20、零非負有理數(shù)：（不是負的有理數(shù)）=正有理數(shù)和零※典型例題考向3：有理數(shù)的分類1、0這個數(shù)是（）A正數(shù)B負數(shù)C整數(shù)D無理數(shù)2、3不是（）A有理數(shù)B整數(shù)C自然數(shù)D負有理數(shù)3、下列說法中，不正確的是（）A有最小正整數(shù)，沒有最小的負整數(shù)B若一個數(shù)是整數(shù)，則它一定是有理數(shù)C0既不是正有理數(shù)，也不是負有理數(shù)D正有理數(shù)和負有理數(shù)組成有理數(shù)4、下列各數(shù)中，是正分?jǐn)?shù)的是（）AB2C0D0.3215、下面說法正確的是（）A有理數(shù)是整數(shù)B有理數(shù)包括整數(shù)和分?jǐn)?shù)