Regulations: ③=2*3*4; ④=3*4*5; ⑤=4*5*6; ⑩=9*10*11...if (1/(⑦))-(1/(⑧)) =(1/(⑧))*□, then what number should be filled in the box.
规定：③=2*3*4；④=3*4*5；⑤=4*5*6；⑩=9*10*11…如果(1/(⑦))-(1/(⑧))=(1/(⑧))*□，那么方框内应填的数是多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>