To make the formula (1/2)+(1/6)+(1/12)+(1/20)+(1/30)+(1/42)+(1/56)+(1/72) +(1/90)+□=1 is established, then what is the number in □.
要使算式(1/2)+(1/6)+(1/12)+(1/20)+(1/30)+(1/42)+(1/56)+(1/72)+(1/90)+□=1成立，则□中的数等于多少．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<result>1/10 = around 0.1</result>