The forest farm planted 618 trees this year, an increase of 3% over last year. How many trees were planted last year?
林场今年种树618棵，比去年增加3%，去年种树多少棵？
<gadget id="calculator">3 / 100</gadget>
<output>3/100 = around 0.03</output>

<gadget id="calculator">1 + (3/100)</gadget>
<output>103/100 = around 1.03</output>

<gadget id="calculator">618 / (103/100)</gadget>
<output>600</output>

<result>600</result>