Guangming Primary School planted 260 trees this year, 20 more than last year's 80%. How many trees were planted last year?
光明小学今年栽树260棵，比去年栽的80%还多20棵，去年栽了多少棵？
<gadget id="calculator">260 - 20</gadget>
<output>240</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">240 / (4/5)</gadget>
<output>300</output>

<result>300</result>