Two trucks of rice, 40 bags of 50 kg each, were transported to the disaster-stricken area in Sichuan by truck. How many kilograms of rice are shipped in total?
用卡车向四川灾区运送了两车大米，每车40袋，每袋50千克．一共运送大米多少千克？
<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<gadget id="calculator">50 * 80</gadget>
<output>4_000</output>

<result>4_000</result>