A square vegetable field with a side length of 80 decimeters is surrounded by a fence. How long is the fence?
一块边长80分米的正方形菜地，四周围上篱笆，篱笆长多少米？
<gadget id="calculator">80 * 4</gadget>
<output>320</output>

<gadget id="calculator">320 / 10</gadget>
<output>32</output>

<result>32</result>