【计算题专项练习】人教版四年级数学下册 第六单元：整数加法运算律推广到小数（含答案与解析）

2025-2026学年四年级数学下册人教版

第六单元计算专项06:整数加法运算律推广到小数

辞日期：___________0用时：___________e评价：___________

♦•一、利用加法运算律填空

1.在横线上填上适当的数。

8.7+16.5+3.5=8.7+(+)20-7.8-2.2=20-(+)

15.6+8.9+4.4+11.1=(15.6+)+(+)

2.在横线上填合适的数。

6.2+19.3+3.8=19.3+(+3.8)

7-3.11-2.89=7-(+)

11.43+6.72+8.57=6.72+(+)

3.在O里填上合适的运算符号，在|里填上合适的数。

(1)20-7.23-2.77=20-(j\(^)|)

(2)34.68-(4.68+0.9)=34.68—______\(^)_______

(3)3.3+5.4+6.7+4.6=(______|+[)(+)

4.在门里填上适当的数，在O里填上适当的运算符号。

(1)5.2+0.74+4.8=5.2+|一|+0.74

(2)4.4+13.57+2.43=4.4+(|[(^)

(3)48.72-0.2-0.8=48.72(。)()

(4)7.6-2.5+24-1.5=(||+)-(~|+[~~|)

(5)146.75-99.3=146.75-100(^^

，二、加法交换律（三个数相加）

(1)0.35+2.7+0.65(2)1.2+5.83+0.8

(3)3.4+0.56+6.6(4)0.78+4.2+0.22

(5)2.5+1.37+7.5(6)5.1+0.9+3.9

(7)0.42+6.5+0.58(8)3.8+2.15+6.2

(9)1.6+0.34+8.4(10)0.5+7.28+9.5

(11)4.3+0.67+5.7(12)2.1+3.82+7.9

♦•三、加法结合律（三个数相加，后两个数凑整）

(1)1.8+0.45+0.55(2)3.2+1.73+2.27

(3)0.6+2.38+7.62(4)5.4+0.89+0.11

(5)2.7+3.52+6.48(6)0.9+4.65+5.35

(7)4.1+0.36+0.64(8)1.3+2.87+7.13

(9)3.5+1.49+8.51(10)0.7+5.24+4.76

(11)2.9+0.53+9.47(12)5.8+1.61+8.39

♦•四、交换律与结合律综合应用（四个数相加，两两凑整）

(1)0.25+3.6+1.75+0.4(2)1.54-0.8+8.5+2.2

(3)63+4.7+5.3+9.7(4)2.4+0.6+7.6+9.4

(5)0.85+3.2+1.15+6.8(6)1.25+5.7+8.75+4.3

(7)3.1+0.9+6.9+9.1(8)0.4+5.6+2.5+7.5

(9)1.3+8.7+0.5+9.5(10)2.8+7.2+3.4+6.6

(11)0.65+4.35+1.2+8.8(12)5.5+4.5+0.7+9.3

♦•五、减法的性质（小数）

(1)5.6-1.25-0.75(2)7.8-2.3-1.7

(3)9.4-0.68-0.32(4)4.9-1.55-2.45

(5)10.2-3.4-6.6(6)6.5-0.8-0.2

(7)8.3-2.17-1.83(8)3.7-0.53-0.47

(9)5.1-1.3-1.7(10)7.2-0.95-0.05

(11)9.6-2.8-3.2(12)4.8-1.12-0.88

参考答案

一、利用加法运算律填空

1.16.53.57.82.24.48.911.1

2.6.23.112.8911.438.57

3.(1)7.23；+；2.77；

(2)4.68；-；0.9；

(3)3.3；6.7；+；5.4；4.6

4.(1)4.8

(2)13.57；+；2.43

(3)-；0.2；+；0.8

(4)7.6；2.4；2.5；1.5

(5)+；0.7

二、加法交换律(三个数相加)

(1)0.35+2.7+0.65

=0.35+0.65+2.7

=1+2.7

=3.7

(2)1.2+5.83+0.8

=1.2+0.8+5.83

=2+5.83

=7.83

(3)3.4+0.56+6.6

=3.4+6.6+0.56

=10+0.56

=10.56

(4)0.78+4.2+0.22

=0.78+0.22+4.2

=1+4.2

=5.2

(5)2.5+1.37+7.5

=2.5+7.5+1.37

=10+1.37

=11.37

(6)5.1+0.9+3.9

=5.1+3.9+0.9

=9+0.9

=9.9

(7)0.42+6.5+0.58

=0.42+0.58+6.5

=1+6.5

=7.5

(8)3.8+2.15+6.2

=3.8+6.2+2.15

=10+2.15

=12.15

(9)1.6+0.34+8.4

=1.6+8.4+0.34

=10+0.34

=10.34

(10)0.5+7.28+9.5

=0.5+9.5+7.28

=10+7.28

-17.28

(11)4.3+0.67+5.7

=4.3+5.7+0.67

=10+0.67

=10.67

(12)2.1+3.82+7.9

=2.1+7.9+3.82

=10+3.82

=13.82

三、加法结合律(三个数相加，后两个数凑整)

(1)1.8+0.45+0.55

=1.8+(0.45+0.55)

=1.8+1

=2.8

(2)3.2+1.73+2.27

=3.2+(1.73+2.27)

=3.2+4

=7.2

(3)0.64-2.384-7.62

=0.6+(2.38+7.62)

=0.6+10

=10.6

(4)5.4+0.89+0.11

=5.4+(0.89+0.11)

=5.4+1

=6.4

(5)2.7+3.52+6.48

=2.7+(3.52+6.48)

=2.7+10

=12.7

(6)0.9+4.65+5.35

=0.9+(4.65+5.35)

=0.9+10

=10.9

(7)4.1+0.36+0.64

=4.1+(0.36+0.64)

=4.1+I

=5.1

(8)1.3+2.87+7.13

=1.3+(2.87+7.13)

=1.3+10

=11.3

(9)3.5+1.49+8.51

=3.5+(1.49+8.51)

=3.5+10

=13.5

(10)0.7+5.24+4.76

=0.7+(5.24+4.76)

=0.7+10

=10.7

(11)2.9+0.53+9.47

=2.9+(0.53+9.47)

=2.9+10

=12.9

(12)5.8+1.61+8.39

=5.8+(1.61+8.39)

=5.8+10

=15.8

四、交换律与结合律综合应用(四个数相加，两两凑整)

(1)0.25+3.6+1.75+0.4

-(0.25+1.75)+(3.6+0.4)

=2+4

=6

(2)1.5+0.8+8.5+2.2

=(1.5+8.5)+(0.8+2.2)

=10+3

=13

(3)0.3+4.7+5.3+9.7

=(0.3+9.7)+(4.7+5.3)

=10+10

=20

(4)2.4+0.6+7.6+9.4

=(2.4+7.6)+(0.6+9.4)

=10+10

=20

(5)0.85+3.24-1.15+6.8

=(0.85+1.15)+(3.2+6.8)

=2+10

=12

(6)1.25+5.7+8.75+4.3

=(1.25+8.75)+(5.7+43)

=10+10

=20

(7)3.1+0.9+6.9+9.1

=(3.1+6.9)+(0.9+9.1)

=10+10

=20

(8)0.4+5.6+2.5+7.5

=(0.4+5.6)+(2.5+7.5)

=6+10

-16

(9)1.3+8.7+0.5+9.5

=(1.3+8.7)+(0.5+9.5)

=10+10

=20

(10)2.8+7.2+3.4+6.6

=(2.8+7.2)+(3.4+6.6)

=10+10

=20

(11)0.65+4.35+1.2+8.8

=(0.65+4.35)+(1.2+8.8)

=5+10

=15

(12)5.5+4.5+0.7+9.3

=(5.5+4.5)+(0.7+9.3)

=10+10

=20

五、减法的性质(小数)

(1)5.6-1.25-0.75

=5.6-(1.25+0.75)

=5.6-2

=3.6

(2)7.8-2.3-1.7

=7.8・(2.3+1.7)

=7.8-4

=3.8

(3)9.4-0.68-0.32

=9.4-(0.68+0.32)

=9.4-1

=8.4

(4)4.9-1.55-2.45

=4.9-(1.55+2.45)

=4.9-4

=0.9

(5)10.2-3.4-6.6

=10.2-<3.44-6.6)

=10.2-10

=0.2

(6)6.5-0.8-0.2

=6.5-(0.8+0.2)

=6.5-1

=5.5

(7)8.3-2.17-1.83

=8.3