A rectangular field is 18 meters long and 50 decimeters wide. A total of 630 kilograms of rapeseed is harvested in this field. How many kilograms per square meter on average?
一块长方形地，长18米，宽50分米，在这块地里一共收油菜630千克．平均每平方米收多少千克？
<gadget id="calculator">50 / 10</gadget>
<output>5</output>

<gadget id="calculator">18 * 5</gadget>
<output>90</output>

<gadget id="calculator">630 / 90</gadget>
<output>7</output>

<result>7</result>