1. 口算。
$0.6×5= $
$0.04×1.8= $
$0.16×0.5= $
$1.25×80= $
$4×0.25= $
$2.8×0.4= $
$32×0.25= $
$0.01×0.01= $
$0.6×5= $
3
$0.04×1.8= $
0.072
$0.16×0.5= $
0.08
$1.25×80= $
100
$4×0.25= $
1
$2.8×0.4= $
1.12
$32×0.25= $
8
$0.01×0.01= $
0.0001
答案
3
0.072
0.08
100
1
1.12
8
0.0001
0.072
0.08
100
1
1.12
8
0.0001
2. 列竖式计算。
$0.107×23= $
$480×0.29= $
$7.25×0.04= $
$0.107×23= $
$480×0.29= $
$7.25×0.04= $
答案
2.461
139.2
0.29
3. 根据$208×75= 15600$,直接写出下列各题的得数。
$208×7.5= $
$2.08×7.5= $
$20.8×7.5= $
$2080×0.75= $
$208×7.5= $
1560
$2.08×7.5= $
15.6
$20.8×7.5= $
156
$2080×0.75= $
1560
答案
1560
15.6
156
1560
15.6
156
1560
4. 在〇里填上“>”“<”或“=”。
$6.9×0.98$
$7.2×1.01$
$1.04×0.84$
$72.4×0.01$
$6.9×0.98$
<
$6.9$$7.2×1.01$
>
$7.2$$1.04×0.84$
>
$0.84$$72.4×0.01$
=
$0.01×72.4$答案
<
>
>
=
>
>
=
5. 计算下面各题,你认为怎样简便就怎样计算。
$1.25×0.32×2.5$
$6.7×3.9+6.1×6.7$
$9.8×1.25$
$2.8×11.4-0.28×14$
$1.25×0.32×2.5$
$6.7×3.9+6.1×6.7$
$9.8×1.25$
$2.8×11.4-0.28×14$
答案
=(1.25×0.8 ) × ( 0.4×2.5)
=1×1
=1
=6.7×(3.9+6.1)
=6.7×10
=67
=9×1.25+0.8×1.25
=11.25+1
=12.25
=2.8×11.4-2.8×1.4
=2.8×(11.4-1.4)
=2.8×10
=28
=1×1
=1
=6.7×(3.9+6.1)
=6.7×10
=67
=9×1.25+0.8×1.25
=11.25+1
=12.25
=2.8×11.4-2.8×1.4
=2.8×(11.4-1.4)
=2.8×10
=28
6. 两名老师带着35名二年级学生去动物园参观,用120元钱买门票够吗?

答案
5.8 ×2+35 ×2.8
=11.6 +98
=109.6(元)
120元>109.6元
答:120元钱够买门票。
=11.6 +98
=109.6(元)
120元>109.6元
答:120元钱够买门票。
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