Uncle Wang's house has a rectangular open space with a length of 12 meters and a width of 9 meters, which is to be used for planting grapes. It is known that each vine occupies an average area of 4 square meters. How many vines can be planted in this open space?
王大伯家有一块长12米、宽9米的长方形空地，准备用来种葡萄，已知每棵葡萄树平均占地4平方米．这块空地共能种多少棵葡萄树？
<gadget id="calculator">9 / 4</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">12 * (9/4)</gadget>
<output>27</output>

<result>27</result>