The distance between the two buildings is 28 meters, and there is a tree every 4 meters. How many trees can there be between the two buildings?
两栋楼之间相距28米，每隔4米载一棵树，两栋楼之间一共可以在多少棵树．
<gadget id="calculator">28 / 4</gadget>
<output>7</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<result>6</result>