(1/2)+(1/6)+(1/12)+(1/20)+(1/30)+(1/42)+(1/56)+(1/72)+(1 /90).
(1/2)+(1/6)+(1/12)+(1/20)+(1/30)+(1/42)+(1/56)+(1/72)+(1/90)．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / 42</gadget>
<output>1/42 = around 0.02381</output>

<gadget id="calculator">1 / 56</gadget>
<output>1/56 = around 0.017857</output>

<gadget id="calculator">1 / 72</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">1 / 90</gadget>
<output>1/90 = around 0.011111</output>

<gadget id="calculator">(1/2) + (1/6) + (1/12) + (1/20) + (1/30) + (1/42) + (1/56) + (1/72) + (1/90)</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>