□口算。
$500×8=$
$900-170=$
$660÷110=$
$51-29=$
$640÷80=$
$72+19=$
$480÷3=$
$45×200=$
$708÷2=$
$105×4=$
$110-95=$
$90×60=$
$510-170=$
$20×55=$
$81-34=$
$980÷14=$
$65-26=$
$1900÷19=$
$900÷6=$
$64-16=$
$47+43=$
$14×40=$
$702÷6=$
$508÷2=$
$120÷24=$
$48×5=$
$4×225=$
$220-50=$
$71-33=$
$390÷13=$
$420÷30=$
$102×30=$
$96-48=$
$28+35=$
$910÷70=$
$180×4=$

1.4000
2.730
3.6
4.22
5.8
6.91
7.160
8.9000
9.354
10.420
11.15
12.5400
13.340
14.1100
15.47
16.70
17.39
18.100
19.150
20.48
21.90
22.560
23.117
24.254
25.5
26.240
27.900
28.170
29.38
30.30
31.14
32.3060
33.48
34.63
35.13
36.720

□用简便方法计算。
$49×25×4$
$37×99$
$125×(8+20)$
$88×125$
$600÷(12×25)$
$450×18$

1.4900
2.3663
3.3500
4.11000
5.2
6.8100