Proportional formula X: 5=40%: 2, X=how many.
比例式X：5=40%：2中，X=多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) * 5</gadget>
<output>2</output>

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

<result>1</result>