Simple operation: 3.6/(1.2+0.6)*2.
简便运算：3.6/(1.2+0.6)*2．
<gadget id="calculator">1.2 + 0.6</gadget>
<output>1.8</output>

<gadget id="calculator">3.6 / 1.8</gadget>
<output>2</output>

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

<result>4</result>