It takes 20 seconds to saw a piece of wood into 5 sections, how many seconds does it take to saw one section?
一根木料锯成5段，用20秒，锯一段用多少秒秒．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>