1+(1/2)+(2/2)+(1/2)+(1/3)+(2/3)+(3/3)+(2/3)+(1/3)+ …+(1/15)+(2/15)+…+(14/15)+(15/15)+(14/15)+(13/15)+…+(2/15)+(1 /15).
1+(1/2)+(2/2)+(1/2)+(1/3)+(2/3)+(3/3)+(2/3)+(1/3)+…+(1/15)+(2/15)+…+(14/15)+(15/15)+(14/15)+(13/15)+…+(2/15)+(1/15)．
<gadget id="calculator">1 + 15</gadget>
<output>16</output>

<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">16 * (15/2)</gadget>
<output>120</output>

<result>120</result>