《2025年天天练口算五年级数学上册人教版》

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计算
70 - 69.3 = 0.7
3.2 × 0.3 = 0.96
2 × 0.2 - 0.4 = 0
4.21 + 5.09 = 9.3
0.8 × 4 = 3.2
3.5 × 0.9 × 2 = 6.3
3.29 - 1.29 = 2
0.5 × 0.12 = 0.06
2.5 × 0.01 × 4 = 0.1
5.61 - 5.11 = 0.5
4.5 × 0.3 = 1.35
3.2 × 4 × 0.5 = 6.4
4.7 - 0.7 = 4
6.1 × 0.1 = 0.61
2.8 × 2 - 5.6 = 0
2.81 + 1.19 = 4
1.4 × 0.7 = 0.98
1.5 - 0.2 × 3 = 0.9
20 - 4.58 = 15.42
1.6 × 0.4 = 0.64
4.5 × 0.2 × 10 = 9
6.78 - 6.08 = 0.7
0.4 × 0.13 = 0.052
19 × 0.1 + 0.1 = 2
2 - 1.1 = 0.9
0.5 × 9 = 4.5
4 × 0.8 - 1.6 = 1.6
1 - 0.09 = 0.91
1.8 × 3 = 5.4
2.3 + 1.2 × 0.3 = 2.66

答案： 解析：这些题目主要考查小数的加减法、乘除法运算，以及四则运算的顺序。需要准确掌握小数运算的方法，注意运算顺序，先乘除后加减，有括号先算括号里的。
答案：
$70 - 69.3 = 0.7$
$3.2 × 0.3 = 0.96$
$2 × 0.2 - 0.4 = 0$
$4.21 + 5.09 = 9.3$
$0.8 × 4 = 3.2$
$3.5 × 0.9 × 2 = 6.3$
$3.29 - 1.29 = 2$
$0.5 × 0.12 = 0.06$
$2.5 × 0.01 × 4 = 0.1$
$5.61 - 5.11 = 0.5$
$4.5 × 0.3 = 1.35$
$3.2 × 4 × 0.5 = 6.4$
$4.7 - 0.7 = 4$
$6.1 × 0.1 = 0.61$
$2.8 × 2 - 5.6 = 0$
$2.81 + 1.19 = 4$
$1.4 × 0.7 = 0.98$
$1.5 - 0.2 × 3 = 0.9$
$20 - 4.58 = 15.42$
$1.6 × 0.4 = 0.64$
$4.5 × 0.2 × 10 = 9$
$6.78 - 6.08 = 0.7$
$0.4 × 0.13 = 0.052$
$19 × 0.1 + 0.1 = 2$
$2 - 1.1 = 0.9$
$0.5 × 9 = 4.5$
$4 × 0.8 - 1.6 = 1.6$
$1 - 0.09 = 0.91$
$1.8 × 3 = 5.4$
$2.3 + 1.2 × 0.3 = 2.66$

得数为 100 的是②③⑦⑧
得数为 70 的是①④⑤⑩

答案： ① 20×0.7×5=20×5×0.7=100×0.7=70
② 125×0.1×8=125×8×0.1=1000×0.1=100
③ 250×0.1×4=250×4×0.1=1000×0.1=100
④ 25×7×0.4=25×0.4×7=10×7=70
⑤ 1.4×100×0.5=140×0.5=70
⑥ 50×50.25-50×30.25=50×(50.25-30.25)=50×20=1000
⑦ 250×0.2+250×0.2=250×0.2×2=50×2=100
⑧ 4×21.9+4×3.1=4×(21.9+3.1)=4×25=100
⑨ 125×0.1×80=125×80×0.1=10000×0.1=1000
⑩ 3.5×25.4-5.4×3.5=3.5×(25.4-5.4)=3.5×20=70
得数为 100 的是②③⑦⑧
得数为 70 的是①④⑤⑩