Plant trees on a slope of 4.5 hectares, each tree covers an area of 3 square meters, how many trees can be planted on this land.
在4.5公顷的坡地上种树，每棵树占地3平方米，这块地可种树多少棵．
<gadget id="calculator">4.5 * 10_000</gadget>
<output>45_000</output>

<gadget id="calculator">45_000 / 3</gadget>
<output>15_000</output>

<result>15_000</result>