The students planted trees on one side of the road, one tree at the beginning of the road, and then planted one tree every 5 meters. A total of 10 trees were planted. How many meters are the distance from the first tree to the tenth tree?
同学们在公路的一边种树，在路的起点种一棵，以后每隔5米种一棵，一共种了10棵，从第一棵到第十棵相距多少米？
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">9 * 5</gadget>
<output>45</output>

<result>45</result>