A rectangular vegetable field is 20 meters long and 15 meters wide. If 21 kilograms of cabbage can be harvested per square meter, how many kilograms of cabbage can be harvested in this field?
一块长方形菜地，长是20米，宽是15米，如果每平方米收白菜21千克，这块地一共可以收白菜多少千克？
<gadget id="calculator">20 * 15 * 21</gadget>
<output>6_300</output>

<result>6_300</result>