Teacher Wang bought a new house and spent 104,000 yuan on decoration, which was 20% less than planned. How much was Mr. Wang's original plan to spend on decoration?
王老师买了新房子，装修用了10.4万元，比计划节约了20%．王老师原计划用于装修的费用是多少万元？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">10.4 / (4/5)</gadget>
<output>13</output>

<result>13</result>