精英家教网 > 小学数学 > 题目详情
1.8×5.46+18×45.4 0.38×102
32÷0.25 15.92-7.56+2.08-2.44
20.06×65+380×2.006-2.006×30
1
1×2
+
1
2×3
+
1
3×4
+…+
1
49×50
9.9+9.99+9.999 0.7777×0.7+0.1111×5.1.
分析:①②⑤⑧运用乘法的分配律进行解答即可.
③把0.25转化成分数,再进行计算即可.
④运用一个数减去两个数,可以用这个数减去这两个数的和.
⑥运用
1
1×2
=
1
1
-
1
2
1
2×3
=
1
2
-
1
3
由此进行解答即可.
⑦把9.9=10-0.1,9.99=10-0.01,由此进行解答即可.
解答:解:①1.8×5.46+18×45.4,
=1.8×5.46+1.8×4.54,
=1.8×(5.46+4.54),
=1.8×10,
=18;

②0.38×102,
=0.38×(100+2),
=0.38×100+0.38×2,
=38+0.76,
=38.76;

③32÷0.25,
=32÷
1
4

=32×4,
=128;

④15.92-7.56+2.08-2.44,
=15.92-(7.56+2.44)+2.08,
=15.92-10+2.08,
=5.92+2.08,
=8;

⑤20.06×65+380×2.006-2.006×30,
=2.006×650+380×2.006-2.006×30,
=2.006×(650+380-30),
=2.006×1000,
=2006;

1
1×2
+
1
2×3
+
1
3×4
+…+
1
49×50

=1-
1
2
+
1
2
-
1
3
+
1
3
-
1
4
+…
1
49
-
1
50

=1-
1
50

=
49
50


⑦9.9+9.99+9.999+,
=(10-0.1)+(10-0.01)+(10-0.001),
=30-0.111,
=29.889;

⑧0.7777×0.7+0.1111×5.1,
=0.1111×4.9+0.1111×5.1,
=0.1111×10,
=1.111;
点评:本题运用乘法的运算定律进行解答即可,考查了学生灵活解决问题的能力.
练习册系列答案
相关习题

科目:小学数学 来源: 题型:

下面各题怎样简便就怎样算.
4.23+3.6-0.23+6.4

5.12+5.12×99
8.5×6÷8.5×6 18÷0.45
50.8÷(26.5-7.5×3) 1.8÷[0.216÷(0.7-0.46)].

查看答案和解析>>

科目:小学数学 来源: 题型:

1.8+0.5= 2.5-0.1= 4.8-0.2= 74+71=
48+10= 24÷12= 68÷0.68= 94.7÷0.1=
61.8÷0.6= 0.8×6.7= 3÷8= 0.12×3=
32= 8.2-2.8= 3.5÷0.7=
4
5
-
1
5
=
1
3
+
1
4
=
1
16
+
7
16
=
5.3+0.5= 46+18=
8.5-1.5= 69+10= 28.8+0.4= 40.5÷0.5=
92.7÷0.3= 0.5×1.3= 16×0.5= 4.4+0.1=
6.1-0.1= 3.3+0.6= 33.2÷0.4= 1÷0.25=
1.5×4= 6.5+1.35= 1.3-1.2=
7
8
-
1
4
=
1
2
+
3
4
=
5
6
-
1
3
=
5.7-1.7= 0.35+0.75=
0.2×1.1= 1.6÷0.4= 10÷4= 3.4÷0.2=
52÷13= 57÷19= 3.7-0.8= 29+92=
8.2+0.7= 6.5-5.6= 4.8÷0.3= 33=
1.25×8=
2
3
+
1
6
=
1
2
-
1
3
=
7
9
+
1
9
=
2.1÷0.3= 3.2×3= 2.8-1.8= 0.9×6.2=

查看答案和解析>>

科目:小学数学 来源: 题型:

计算
1.8×5.46+18×0.454 3+5+8+11+14+17+20+22
1+2+3+…+50
1
1×2
+
1
2×3
+
1
3×4
+…+
1
49×50
2012×
2010
2011
0.7777×0.7+0.1111×5.1.

查看答案和解析>>

科目:小学数学 来源: 题型:解答题

1.8×5.46+18×45.40.38×102
32÷0.2515.92-7.56+2.08-2.44
20.06×65+380×2.006-2.006×30数学公式
9.9+9.99+9.9990.7777×0.7+0.1111×5.1.

查看答案和解析>>

同步练习册答案