Simple calculation: (45+240)/(20-5).
简算：(45+240)/(20-5)．
<gadget id="calculator">45 + 240</gadget>
<output>285</output>

<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">285 / 15</gadget>
<output>19</output>

<result>19</result>