1. 直接写出得数。
$1 - 0.09 =$ $10 + 8.6 =$ $23.5 - 6.6 =$
$1 + 0.38 =$ $7.8 + 2 =$ $4.8 + 0.52 =$
$4.69 - (1.69 + 0.5) =$ $1 - 0.27 - 0.73 =$ $0.8×4÷4×0.8 =$
$0.5×0.88 =$ $20×0.08 =$ $0.66×8 =$
$0.49×0.8 =$ $0.9×0.12 =$ $0.5×1.2 =$
$2.8×0.6 =$ $0.8×0.4 =$ $0.28×100 =$

$1 - 0.09 = \boldsymbol{0.91}$
$10 + 8.6 = \boldsymbol{18.6}$
$23.5 - 6.6 = \boldsymbol{16.9}$
$1 + 0.38 = \boldsymbol{1.38}$
$7.8 + 2 = \boldsymbol{9.8}$
$4.8 + 0.52 = \boldsymbol{5.32}$
$4.69 - (1.69 + 0.5) = \boldsymbol{2.5}$
$1 - 0.27 - 0.73 = \boldsymbol{0}$
$0.8×4÷4×0.8 = \boldsymbol{0.64}$
$0.5×0.88 = \boldsymbol{0.44}$
$20×0.08 = \boldsymbol{1.6}$
$0.66×8 = \boldsymbol{5.28}$
$0.49×0.8 = \boldsymbol{0.392}$
$0.9×0.12 = \boldsymbol{0.108}$
$0.5×1.2 = \boldsymbol{0.6}$
$2.8×0.6 = \boldsymbol{1.68}$
$0.8×0.4 = \boldsymbol{0.32}$
$0.28×100 = \boldsymbol{28}$

2. 列竖式计算。
$60.9 + 9.43 =$ $40 - 25.705 =$ $670×0.7 =$
$7.06×1.5 =$ $7.42×3.2 =$ $2.7×0.12 =$

60.90
+ 9.43
-------
70.33
60.9 + 9.43 = 70.33
40.000
-25.705
-------
14.295
40 - 25.705 = 14.295
670
× 0.7
------
469.0
670×0.7 = 469
7.06
× 1.5
------
3530
706
------
10.590
7.06×1.5 = 10.59
7.42
× 3.2
------
1484
2226
------
23.744
7.42×3.2 = 23.744
2.7
×0.12
------
54
27
------
0.324
2.7×0.12 = 0.324

3. 计算下列各题，能简算的要简算。
$4.06×3 + 17.5 - 5$ $9.2×5.28 + 4.72×9.2$
$12 + 1.25×0.08$ $35.8 + 4.2×0.06$

$4.06×3 + 17.5 - 5$
=12.18 + 17.5 - 5
=29.68 - 5
=24.68
$9.2×5.28 + 4.72×9.2$
=9.2×(5.28+4.72)
=9.2×10
=92
$12 + 1.25×0.08$
=12 + 0.1
=12.1
$35.8 + 4.2×0.06$
=35.8 + 0.252
=36.052