小学数学 小数混合运算.docx
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小学数学小数混合运算
类型二小数混合运算
【知识讲解】
1.运算顺序
小数四则混合运算的顺序与整数四则混合运算的顺序完全相同,整数四则混合运算的运算定律对小数同样适用。
2.运算方法
一个算式里,如果只含有同一级运算,要从左往右依次计算,如果含有两级运算,要先做第二级运算,后做第一级运算,如果有括号,要先算小括号里面的,再算中括号里面的,最后算括号
外面的。
【巩固练习】资料来源微信:
b684951
一、直接写得数。
0.5÷5=0.4÷0.2=0.48÷0.02=
5÷0.5=0.4×0.2=0÷0.02=
7.3+3.7=0.15×4=1.78+2.2=
12﹣9.6+0.4=7.5÷25=0.3÷0.01=
4÷0.8=1.8×0.5﹣0.4=0.16×5=
6.6÷0.66=1.23×0.3=0.25×4÷0.25×4=
0.25×0.5×8=0.17+3.4+0.43=0.4×4÷0.4×4=
1÷0.125=5.8+2.32+0.68+4.2=1.25×8.8=
(6+0.3)÷2.1=0.45÷(2﹣0.5)=
二、脱式计算,能简算的要简算。
9.07﹣22.78÷3.412.5×17.8×0.8
6.3×1019.4×5.8+10.6×5.8
14﹣5.34﹣4.666.29×4.6+4.6×13.71
5.4﹣0.15×2.613÷2.5÷0.4
1.25×2.5×3.2(9.6+1.48÷3.7)÷8.
0.69×4.2+0.69×5.8(8+0.8)×1.25
4.95+12.08﹣5.376.15×9.4﹣4.2
62.8+2.02×9.50.25×3.8×0.4
32.8×10.5÷0.612.7+11.5÷5
9.07﹣22.78÷3.41
.2×2.5+0.8×2.5
2.8×4.5+5.5×2.8930÷5÷0.6
(2.25+27.75÷1.5)×1.612.5×2.5×3.2
[5﹣1.7÷(2﹣1)]×120×2.5÷(10×0.7+3)
7.2×0.8+1.046.83×7.5+6.83×2.5
1.08×0.88÷0.272.05÷0.82
+33.6
3.5×0.99(3.168+1.9)÷(10﹣9.44)
1.2×3﹣6.5÷2.51.8×2.4÷3.6+0.8.
(4.5×11.1×4.8)÷(3.33×0.8×0.9)
3.5×1.25+1.25+3.5÷0.8
三、列式计算。
1.一个数比2.01与2.29的和多1.2,这个数是多少?
2.3.58加上7.08与5.1的差,和是多少?
3.0.12除以12.6与6.6的差,商是多少?
4.一个数的11倍是28.6,这个数的25倍是多少?
5.9除0.45的商加上32.72,得多少?
6.20.2减去2.2的差,除以3与2
的积,商是多少?
7.0.6与2.5的积除13.8减2.85的差,结果是多少?
8.一个数比2.02与3.28的和多1.3,这个数是多少?
9.从100.86里减去10.54与20.86的和,差是多少?
10.用14.81与5.19的和,乘以它们的差,积是多少?
11.126.8与15.7的和,乘以1.02,积是多少?
12.0.6乘0.8的积,加上0.12后,再除以1.2,商是多少?
参考答案:
一、【答案】
0.1224100.080
110.63.982.80.33050.5
0.8100.36916141681311
30.3
二、【答案】
9.07﹣22.78÷3.4
=9.07﹣6.7
=2.37
12.5×17.8×0.8
=(12.5×0.8)×17.8
=10×17.8
=178
6.3×101
=6.3×(100+1)
=6.3×100+6.3×1
=630+6.3
=636.3
9.4×5.8+10.6×5.8
=5.8×(9.4+10.6)
=5.8×20
=116
14﹣5.34﹣4.66
=14﹣(5.34+4.66)
=14﹣10
=4
6.29×4.6+4.6×1
3.71
=4.6×(6.29+13.71)
=4.6×20
=92
5.4﹣0.15×2.6
=5.4﹣0.39
=5.01
13÷2.5÷0.4
=13÷(2.5×0.4)
=13÷1
=13
1.25×2.5×3.2
=1.25×2.5×(0.8×4)
=(1.25×0.8)×(2.5×4)
=1×10
=10
(9.6+1.48÷3.7)÷8
=(9.6+0.4)÷8
=10÷8
=1.25
0.69×4.2+0.69×5.8
=0.69×(4.2+5.8)
=0.69×10
=6.9
(8+0.8)×1.25
=8×1.25+0.8
×1.25
=10+1
=11
4.95+12.08﹣5.37
=17.03﹣5.37
=11.66
6.15×9.4﹣4.2
=57.81﹣4.2
=53.61
62.8+2.02×9.5
=62.8+19.19
=81.99
0.25×3.8×0.4
=(0.25×0.4)×3.8
=0.1×3.8
=0.38
32.8×10.5÷0.6
=344.4÷0.6
=574
12.7+11.5÷5
=12.7+2.3
=15
9.07﹣22.78÷3.4
=9.07﹣6.7
=2.37;
1.2×2.5+0.8×2.5
=(1.2+0.8)×2.5
=2×2.5
=5;
2.8×4.5+5.5×2.8
=2.8×(4.5+5.5)
=2.8×10
=28
930÷5÷0.6
=930÷(5×0.6)
=930÷3
=310
(2.25+27.75
÷1.5)×1.6
=(2.25+18.5)×1.6
=20.75×1.6
=33.2
12.5×2.5×3.2
=12.5×2.5×(0.8×4)
=(12.5×0.8)×(2.5×4)
=1
0×10
=100
[5﹣1.7÷(2﹣1)]×1
=[5﹣1.7÷1]×1,
=[5﹣1.7]×1,
=3.3×1,
=3.3;
20×2.5÷(10×0.7+3),
=20×2.5÷(7+3),
=20×2.5÷10,
=50÷10,
=5.
7.2×0.8+1.04
=5.76+1.04
=6.8
6.83×7.5+6.83×2.5
=6.83×(7.5+2.5)
=6.83×10
=68.3
1.08×0.88÷0.27
=0.9504÷0.27
=3.52
2.05÷0.82+33.6
=2.5+33.6
=36.1
3.5×0.99
=3.5×(1﹣0.01)
=3.5×1﹣3.5×0.01
=3.5﹣0.035
=3.465
(3.1
68+1.9)÷(10﹣9.44)
=5.068÷0.56
=9.05
1.2×3﹣6.5÷2.5
=3.6﹣2.6
=1
1.8×2.4÷3.6+0.8
=4.32÷3.6+0.8
=1.2+0.8
=2
(4.5×11.1×4.8)÷(3.33×0.8×0.9)
=
=
=100
3.5×1.25+1.25+3.5
÷0.8
=3.5×1.25+1.25+3.5×1.25
=(3.5+1+3.5)×1.25
=8×1.25
=10
三、【答案】
1.2.01+2.29+1.2
=4.3+1.2
=5.5
答:
这个数是5.5。
2.3.58+(7.08﹣5.1)
=3.58+
1.98
=5.56
答:
和是5.56。
3.0.12÷(12.6﹣6.6)
=0.12÷6
=0.02
答:
商是0.02。
4.28.6÷11×25
=2.6×25
=65
答:
这个数的25倍是65。
5.
0.45÷9+32.72
=0.05+32.72
=32.77
答:
得32.77。
6.(20.2﹣2.2)÷(3×2)
=18÷6
=3
答:
商是3。
7.(13.8﹣2.85)÷(0.6×2.5)
=10.95÷1.5
=7.3
答:
结果是7.3。
8.(2.02+3.28)+1.3
=5.3+1.3
=6.6
答:
这个数是6.6。
9.100.86﹣(10.54+20.86)
=100.86﹣31.4
=69.46
答:
差是69.46。
10.(14.81+5.19)×(14.81﹣5.19)
=20×9.62
=192.4;
答:
积是192.4;
11.(126.8+15.7)×1.02
=142.5×1.02
=145.35;
答:
积是145.35;
12.(0.6×0.8+0.
12)÷1.2,
=0.6÷1.2,
=0.5.
答:
商是0.5。