A rectangular open space is 45 meters long and 30 meters wide. If one poplar is planted every 3 square meters, how many poplars can be planted in total?
一块长方形空地，长为45米，宽为30米，如果每3平方米种一棵杨树，一共可以种多少棵杨树？
<gadget id="calculator">30 / 3</gadget>
<output>10</output>

<gadget id="calculator">45 * 10</gadget>
<output>450</output>

<result>450</result>