Xingwang Orchard has a bumper harvest of walnuts this year, with an output of 7,800 kilograms, an increase of 30% over last year. What was the output of walnuts last year?
兴旺果园今年核桃大丰收，产量达到7800千克，比去年增产三成，去年核桃产量是多少？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 + (3/10)</gadget>
<output>13/10 = around 1.3</output>

<gadget id="calculator">7_800 / (13/10)</gadget>
<output>6_000</output>

<result>6_000</result>