Plant trees between two buildings 180 meters apart, and plant one tree every 30 meters. How many trees are planted in total?
在相距180米的两幢楼之间种树，每隔30米栽一棵，共栽多少棵．
<gadget id="calculator">180 / 30</gadget>
<output>6</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<result>5</result>