Calculation: 10*(x-2)/2=2*(x+0.5)/0.5.
计算：10*(x-2)/2=2*(x+0.5)/0.5．
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">2 / 0.5</gadget>
<output>4</output>

<gadget id="calculator">4 * 0.5</gadget>
<output>2</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">12 / 1</gadget>
<output>12</output>

<result>12</result>