A fence is built around a square lawn with a side length of 40 meters, and a wooden stake is placed every 2 meters. How many wooden stakes are needed in total?
在一块边长是40米的正方形草坪周围围篱笆，每隔2米打一根木桩，一共需要多少根木桩．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<result>80</result>