A square vegetable field has a side length of 10 meters. If 9 kilograms of cabbage can be harvested per square meter, how many kilograms of cabbage can be harvested in this field?
一块正方形菜地，边长是10米，如果每平方米收白菜9千克，这块地可以收白菜多少千克？
<gadget id="calculator">10 * 10 * 9</gadget>
<output>900</output>

<result>900</result>