Known proportional formula (5/6): 3=10: x, then, where x=how many.
已知比例式(5/6)：3=10：x，那么，其中的x=多少．
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">6 / 5</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">30 * (6/5)</gadget>
<output>36</output>

<result>36</result>