Calculation: (1/(1*2))+(2/(1*2*3))+(3/(1*2*3*4))+…+(6/(1*2*3* 4*5*6*7)).
计算：(1/(1*2))+(2/(1*2*3))+(3/(1*2*3*4))+…+(6/(1*2*3*4*5*6*7))．
<gadget id="calculator">1 * 2 * 3 * 4 * 5 * 6 * 7</gadget>
<output>5_040</output>

<gadget id="calculator">1 / 5_040</gadget>
<output>1/5_040 = around 0.000198</output>

<gadget id="calculator">1 - (1/5_040)</gadget>
<output>5_039/5_040 = around 0.999802</output>

<result>5_039/5_040 = around 0.999802</result>