【计算题专项练习】人教版四年级数学下册第六单元06：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日期：日期：用时：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。_____3．在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－（）（2）34.68－（4.68＋0.9）＝34.68－（3）3.3＋5.4＋6.7＋4.6＝（＋）（＋）4．在里填上适当的数，在里填上适当的运算符号。（1）5.2＋0.74＋4.8＝5.2＋＋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＋2.4－1.5＝（＋）－（＋）（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)1.5+0.8+8.5+2.2(3)0.3+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1．16.53.57.82.24.48.911.12．6.23.112.8911.438.573．（1）7.23；＋；2.77；

（2）4.68；－；0.9；（3）3.3；6.7；＋；5.4；4.64．（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)0.6+2.38+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+1

=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+3.2+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+4.3)

=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-(3.4+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-(2.17+1.83)

=8.3-4

=4.3(8)3.7-0.53-0.47

=3.7-(0.53+