Known (1/6)=(1/(2*3))=(1/2)-(1/3), (1/12)=(1/(3*4))=(1/3 )-(1/4), (1/20)=(1/(4*5))=(1/4)-(1/5)... Calculate (1/6)+(1/12)+( 1/20)+(1/30).
已知(1/6)=(1/(2*3))=(1/2)-(1/3)，(1/12)=(1/(3*4))=(1/3)-(1/4)，(1/20)=(1/(4*5))=(1/4)-(1/5)…计算(1/6)+(1/12)+(1/20)+(1/30)．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<result>5/6 = around 0.833333</result>