Insert a wooden stick vertically into the bottom of the water and find that it is 50cm wet. If the wooden stick is inserted vertically into the bottom of the water upside down, the wet part will be 20cm longer than half of it. So how long is the stick in cm?
把一根木棍竖直的插入水底，发现湿了50cm．如果再将木棍倒转竖直的插入水底，这时湿的部分总共比其一半长20cm．那么木棍长多少cm．
<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<gadget id="calculator">100 - 20</gadget>
<output>80</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">80 / (1/2)</gadget>
<output>160</output>

<result>160</result>