A rectangular piece of land is 60 meters long and 30 meters wide. Trees are planted on the four sides with a distance of 6 meters. There is one tree on each of the four corners. How many trees are planted in total?
一块长方形地，长为60米，宽为30米，在四边上植树，株距6米，四个角上已各有一棵，一共植树多少棵？
<gadget id="calculator">60 + 30</gadget>
<output>90</output>

<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">90 * (1/3)</gadget>
<output>30</output>

<gadget id="calculator">30 - 4</gadget>
<output>26</output>

<result>26</result>