1. 直接写出得数。
$0.4×0.6=$
$1.2×0.4=$
$2.3×0.5=$
$3.1×0.02=$
$0.32×0.8=$
$3.7×0.6=$
$5.7×0.9=$
$8.5×0.7=$
$1.8×0.3=$
$2.4×4=$
$1.4×0.3=$
$0.6×0.15=$
$2.5×0.4=$
$0.8×0.9=$
$0.7×0.5=$
$2.4×0.5=$
$1.25×0.8=$
$125×0.4=$

$0.4×0.6=0.24$
$1.2×0.4=0.48$
$2.3×0.5=1.15$
$3.1×0.02=0.062$
$0.32×0.8=0.256$
$3.7×0.6=2.22$
$5.7×0.9=5.13$
$8.5×0.7=5.95$
$1.8×0.3=0.54$
$2.4×4=9.6$
$1.4×0.3=0.42$
$0.6×0.15=0.09$
$2.5×0.4=1$
$0.8×0.9=0.72$
$0.7×0.5=0.35$
$2.4×0.5=1.2$
$1.25×0.8=1$
$125×0.4=50$

2. 列竖式计算。
$3.3×0.15=$
$0.12×2.05=$
$3.14×2.9=$
$0.78×4.5=$
$1.6×1.8=$
$2.8×0.16=$
$3.7×0.8=$
$0.25×3.9=$
$2.25×0.18=$

$3.3×0.15=0.495$
$\begin{array}{r}3.3\\×0.15\\\hline165\\33\\\hline0.495\end{array}$
$0.12×2.05=0.246$
$\begin{array}{r}2.05\\×0.12\\\hline410\\205\\\hline0.2460\end{array}$
$3.14×2.9=9.106$
$\begin{array}{r}3.14\\×\ \ 2.9\\\hline2826\\628\\\hline9.106\end{array}$
$0.78×4.5=3.51$
$\begin{array}{r}0.78\\×\ \ 4.5\\\hline390\\312\\\hline3.510\end{array}$
$1.6×1.8=2.88$
$\begin{array}{r}1.6\\×1.8\\\hline128\\16\\\hline2.88\end{array}$
$2.8×0.16=0.448$
$\begin{array}{r}2.8\\×0.16\\\hline168\\28\\\hline0.448\end{array}$
$3.7×0.8=2.96$
$\begin{array}{r}3.7\\×0.8\\\hline2.96\end{array}$
$0.25×3.9=0.975$
$\begin{array}{r}0.25\\×\ \ 3.9\\\hline225\\75\\\hline0.975\end{array}$
$2.25×0.18=0.405$
$\begin{array}{r}2.25\\×0.18\\\hline1800\\225\\\hline0.4050\end{array}$