1. 直接写出得数。
7×60 =
20×7 =
30×9 =
80×5×6 =
6×900 =
8×30 =
6×600 =
20×5×7 =
100×5 =
20×5 =
700×5 =
50×4 + 16 =
20×8 =
70×9 =
4×900 =
6×70 - 20 =
50×4 =
400×8 =
48 + 96 =
90×8 - 28 =
170 - 18 =
5×600 =
90×5 =
36 + 30×4 =
5×500 =
602×7≈
71×8≈
80×3 - 30 =
400×3 =
892×3≈
699×5≈
240 - 80×2 =

7×60 = 420
20×7 = 140
30×9 = 270
80×5×6 = 2400
6×900 = 5400
8×30 = 240
6×600 = 3600
20×5×7 = 700
100×5 = 500
20×5 = 100
700×5 = 3500
50×4 + 16 = 216
20×8 = 160
70×9 = 630
4×900 = 3600
6×70 - 20 = 400
50×4 = 200
400×8 = 3200
48 + 96 = 144
90×8 - 28 = 692
170 - 18 = 152
5×600 = 3000
90×5 = 450
36 + 30×4 = 156
5×500 = 2500
602×7≈4200
71×8≈560
80×3 - 30 = 210
400×3 = 1200
892×3≈2700
699×5≈3500
240 - 80×2 = 80

2. 计算下面各题。
356 - 70×2
100×4 - 243
80×3 - 98
(256 + 144)×8
(986 - 86)×9
7×(357 + 343)

356 - 70×2 = 216
100×4 - 243 = 157
80×3 - 98 = 142
(256 + 144)×8 = 3200
(986 - 86)×9 = 8100
7×(357 + 343) = 4900

(1) $△ + △ + △ = 2700$
$△ × ◯ = 4500$
$△ = (\quad) \quad ◯ = (\quad)$
(2) $□ + □ + \star + \star + \lozenge = 860$
$□ + \star = 400$
$\lozenge = (\quad)$

(1) 900 5
(2) 60