There is a rectangular vegetable field with a length of 30 meters and a width of 20 meters. If 9 kilograms of vegetables are harvested per square meter, how many kilograms of vegetables can be harvested in this vegetable field?
有一块长方形菜地，长是30米，宽是20米．如果每平方米收菜9千克，这块菜地可以收菜多少千克？
<gadget id="calculator">30 * 20 * 9</gadget>
<output>5_400</output>

<result>5_400</result>