说理:
8个十 38752
8个百 43800
8个千 24784
8个万 84560
40×(980÷28)
328÷(104÷13)
①250-250÷25×2
②18÷ ×
③5.2÷0.4÷2.5
④(34- )÷17
⑤4.3×1.75-1.75+ ×6.7
⑥ ×[(72.8-69.6)÷ ]
(+)×9= 1.5×100= 99×0.8+0.8= 42=
+= 7﹣= ×= ÷=