应用运算律,用简便方法计算.① ②12.5×0.4×0.8×2.5.
竖式计算,带*的验算.325+487 *402﹣275 684+139.
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用竖式计算并演算.139+682= 701﹣573= 452﹣189=
684+235=验算: 902﹣637=验算: 527+343=验算: 485+87=验算:
(1)从熊猫馆到飞禽馆最远要走多少米?(2)老虎馆到熊猫馆比老虎馆到飞禽馆近多少米?