【计算题专项练习】人教版四年级数学下册第六单元07：整数加法运算律推广到小数“思维拓展”（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07：整数加法运算律推广到小数“思维拓展”日期：日期：用时：评价：一、分组凑整(1)0.7+0.77+0.777+0.23+0.223 (2)1.25+3.75+2.4+7.6(3)0.9+0.99+0.999+0.1+0.01+0.001 (4)2.5+1.8+7.5+8.2(5)0.66+0.34+0.55+0.45+0.2 (6)3.14+5.86+2.3+7.7(7)0.88+0.12+0.99+0.01+1.5 (8)4.6+5.4+0.78+0.22+3(9)0.5+0.55+0.45+0.5+0.6 (10)1.1+2.2+3.3+6.7+7.8+8.9二、拆分凑整(1)8.9+8.99+8.999+0.3 (2)19.9+19.99+19.999+0.3(3)5.98+5.99+6.01+6.02 (4)9.95+9.96+9.97+9.98+9.99+0.25(5)7.8+7.9+8+8.1+8.2 (6)10.1+10.2+10.3+9.7+9.8+9.9(7)3.99+4.98+5.97+0.06 (8)12.9+12.99+12.999+0.3(9)6.5+6.6+6.7+6.8+6.9+3.5 (10)199.9+19.9+1.9+0.3三、减法的性质(1)30.5-7.2-2.8-0.5 (2)50-12.3-7.7-15.6-4.4(3)18.75-3.4-6.6-8.75 (4)45.6-(5.6+12.5)(5)25.4-2.7-7.3-5.4 (6)60-18.9-11.1-15.3-4.7(7)100.1-50.5-9.5-0.1 (8)36.8-(6.8+3.2+6.8)(9)15.25-4.75-5.25-0.25 (10)72.3-12.1-7.9-22.3-8.5-1.5参考答案一、分组凑整(1)原式=(0.77+0.23)+(0.777+0.223)+0.7

=1+1+0.7

=2.7(2)原式=(1.25+3.75)+(2.4+7.6)

=5+10

=15(3)原式=(0.9+0.1)+(0.99+0.01)+(0.999+0.001)

=1+1+1

=3(4)原式=(2.5+7.5)+(1.8+8.2)

=10+10

=20(5)原式=(0.66+0.34)+(0.55+0.45)+0.2

=1+1+0.2

=2.2(6)原式=(3.14+5.86)+(2.3+7.7)

=9+10

=19(7)原式=(0.88+0.12)+(0.99+0.01)+1.5

=1+1+1.5

=3.5(8)原式=(4.6+5.4)+(0.78+0.22)+3

=10+1+3

=14(9)原式=(0.5+0.5)+(0.55+0.45)+0.6

=1+1+0.6

=2.6(10)原式=(1.1+8.9)+(2.2+7.8)+(3.3+6.7)

=10+10+10

=30二、拆分凑整(1)原式=(8.9+0.1)+(8.99+0.01)+(8.999+0.001)+(0.3−0.1−0.01−0.001)

=9+9+9+(0.3−0.111)

=27+0.189

=27.189(2)原式=(19.9+0.1)+(19.99+0.01)+(19.999+0.001)+(0.3−0.1−0.01−0.001)

=20+20+20+(0.3−0.111)

=60+0.189=60.189(3)原式=(5.98+6.02)+(5.99+6.01)

=12+12

=24(4)原式=(9.95+0.05)+(9.96+0.04)+(9.97+0.03)+(9.98+0.02)+(9.99+0.01)+(0.25-0.05-0.04-0.03-0.02-0.01)

=10+10+10+10+10+0.1

=50.1(5)原式=(7.8+8.2)+(7.9+8.1)+8

=16+16+8

=40(6)原式=(10.1+9.9)+(10.2+9.8)+(10.3+9.7)

=20+20+20

=60(7)原式=(3.99+0.01)+(4.98+0.02)+(5.97+0.03)

=4+5+6

=15(8)原式=(12.9+0.1)+(12.99+0.01)+(12.999+0.001)+(0.3−0.1−0.01−0.001)

=13+13+13+(0.3−0.111)

=39+0.189=39.189(9)原式=(6.5+3.5)+(6.6+6.9)+(6.7+6.8)

=10+13.5+13.5

=37(10)原式=199.9+19.9+1.9+0.1+0.1+0.1

=(199.9+0.1)+(19.9+0.1)+(1.9+0.1)

=200+20+2

=222三、减法的性质(1)原式=(30.5-0.5)-(7.2+2.8)

=30-10

=20(2)原式=50-(12.3+7.7)-(15.6+4.4)

=50-20-20

=10(3)原式=(18.75-8.75)-(3.4+6.6)

=10-10

=0(4)原式=45.6-5.6-12.5

=40-12.5

=27.5(5)原式=(25.4-5.4)-(2.7+7.3)

=20-10

=10(6)原式=60-(18.9+11.1)-(15.3+4.7)

=60-30-20

=10(7)原式=(100.1-0.1)-(50.5+9.5)

=100-60

=40(8