Plant trees between two electric poles 100 meters apart, one tree every 10 meters, how many trees were planted in total.
在相距100米的两根电线杆之间种树，每隔10米一棵，共栽了多少棵．
<gadget id="calculator">100 / 10</gadget>
<output>10</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<result>9</result>