It is known that 50% of a number is 80, what is this number?
已知一个数的50%是80，这个数是多少．
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

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

<result>160</result>