一、口算。
$0.8×2= $ $1.9×5= $ $5.1×3= $
$0.8×0.2= $ $1.9×0.5= $ $5.1×0.3= $
$27×0.2= $ $1.3×8= $ $35×0.4= $
$2.7×0.2= $ $1.3×0.8= $ $0.35×0.4= $
$1.5×0.7= $ $0.5×0.23= $ $0.8×0.9= $
$3.3×0.4= $ $1.2×0.6= $ $1.5×0.5= $
$1.3×0.6= $ $3.2×0.5= $ $1.1×0.8= $
$3.1×0.6= $ $10.2×0.3= $ $2.2×0.3= $
$2.1×0.7= $ $0.08×1.5= $ $0.04×8= $
$1.3×0.2= $ $0.4×5.8= $ $8.5×20= $

一、1.6 9.5 15.3
0.16 0.95 1.53
5.4 10.4 14
0.54 1.04 0.14
1.05 0.115 0.72
1.32 0.72 0.75
0.78 1.6 0.88
1.86 3.06 0.66
1.47 0.12 0.32
0.26 2.32 170

二、根据$854×32= 27328$,直接写出下面各题的得数。
$85.4×3.2=$ $0.854×3.2=$ $0.854×0.32=$
$854×0.32=$ $8.54×3.2=$ $854×3.2=$
$854×0.032=$ $85.4×0.32=$ $8.54×32=$
$0.854×32=$ $0.0854×32=$ $85.4×0.032=$
$85.4×32=$ $0.854×0.032=$ $8.54×0.32=$
$0.0854×0.32=$ $8.54×0.032=$ $0.0854×3.2=$

二、273.28 2.7328 0.27328
273.28 27.328 2732.8
27.328 27.328 273.28
27.328 2.7328 2.7328
2732.8 0.027328 2.7328
0.027328 0.27328 0.27328