Plant sweet potatoes in a rectangular area with a length of 30 meters and a width of 15 meters. Plant one tree in an average of 15 square decimeters, and harvest 2.5 kilograms of sweet potatoes on average. How many kilograms of sweet potatoes are harvested in this field?
在一块长30米，宽15米得长方形地理栽白薯，平均15平方分米栽一棵，平均每棵收白薯2.5千克，这块地共收白薯多少千克？
<gadget id="calculator">100 / 15</gadget>
<output>20/3 = around 6.666667</output>

<gadget id="calculator">30 * 15 * (20/3) * 2.5</gadget>
<output>7_500</output>

<result>7_500</result>