一、口算。
$1.4 + 4.46=$ $1.786\times1000=$ $400\div2.5\div8=$
$0.8\times1.1=$ $7.2\div18=$ $4.8\times(11.4 - 1.4)=$
$23.1\div0.7=$ $10 - 3.7=$ $5.47 - 1.8 - 3.2=$
$0.65\times40=$ $13.5\div9=$ $0.99 + 99\times0.99=$
$3.1 + 0.09=$ $0.55\times2=$ $(1.01 + 0.2)\times100=$
$2.5\times0.04=$ $0.5\div0.05=$ $1.5 - 0.5\times0.6=$
$4.6 + 0.75=$ $2.4 - 1.07=$ $4.6 + 7.1 + 2.9=$
$0.5\times0.26=$ $8\div0.08=$ $26\div(1 - 0.9)=$
$1.2\div0.3=$ $0.72\times0.2=$ $12.6\times0.5 - 4.03=$
$2.8 - 0.58=$ $15.1 + 4.9=$ $0.57 + 0.32\div1.6=$

5.86 1786 20
0.88 0.4 48
33 6.3 0.47
26 1.5 99
3.19 1.1 121
0.1 10 1.2
5.35 1.33 14.6
0.13 100 260
4 0.144 2.27
2.22 20 0.77

二、计算下面各题，怎样简便就怎样计算。
$12.5\times1.4\times0.8\times0.5$ $42 - 47.5\div1.9\times0.16$ $(5.3 - 5.88\div2.1)\times0.36$

7 38 0.9