The current price of a notebook computer is only 3,500 yuan, which is 30% lower than the original price. Do the math, how much does each notebook cost?
一种笔记本电脑现价只卖3500元，比原价时降低了30%．算一算，这种笔记本原来每台多少元？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">3_500 / (7/10)</gadget>
<output>5_000</output>

<result>5_000</result>