Question

直接寫得數(shù) 9-1.8=	4÷0.5=	1.4×0.5=	5.7÷0.3=	0.5×2.4=
1.53+0.8=	3.9-0.39=	0.25×12=	0.51÷0.3=	5.5÷10=

Answer 1

分析：①⑥⑦注意數(shù)位對(duì)齊；②把被除數(shù)和除數(shù)分別擴(kuò)大10倍再計(jì)算；③⑤⑧先算14×5、5×24、25×12，然后在結(jié)果中從后向前數(shù)出兩位，點(diǎn)上小數(shù)點(diǎn)；④⑨把被除數(shù)和除數(shù)分別擴(kuò)大10倍，再計(jì)算；⑩把5.5縮小0倍，即把5.5的小數(shù)點(diǎn)向左移動(dòng)一位即可．

解答：解：9-1.8=7.2；         4÷0.5=8；          1.4×0.5=0.7；         5.7÷0.3=19；           0.5×2.4=1.2；
1.53+0.8=2.33；         3.9-0.39=3.51；     0.25×12=3；           0.51÷0.3=1.7；         5.5÷10=0.55；

點(diǎn)評(píng)：此題考查了小數(shù)的加、減、乘、除運(yùn)算，根據(jù)題目特點(diǎn)，靈活解答．