(1/4) of a number is 50, what is (1/2) of this number.
一个数的(1/4)是50，这个数的(1/2)是多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">50 / (1/4)</gadget>
<output>200</output>

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

<gadget id="calculator">200 * (1/2)</gadget>
<output>100</output>

<result>100</result>