100,000 sheets of paper are stacked up to a height of 8400cm. How many mm is each paper thick?
100000张纸摞起来高8400cm．每张纸厚多少mm？
<gadget id="calculator">8_400 / 100_000</gadget>
<output>21/250 = around 0.084</output>

<gadget id="calculator">(21/250) * 10</gadget>
<output>21/25 = around 0.84</output>

<result>21/25 = around 0.84</result>