For a bunch of watermelons, (1/4) and 4 of the total number are sold for the first time, and the remaining (1/2) and 2 are sold for the second time, and there are 2 left. How many watermelons are in this pile?
一堆西瓜，第一次卖出总个数的(1/4)又4个，第二次卖出余下的(1/2)又2个，还剩2个．这堆西瓜共有多少个？
<gadget id="calculator">2 + 2</gadget>
<output>4</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 / (1/2)</gadget>
<output>8</output>

<gadget id="calculator">8 + 4</gadget>
<output>12</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">12 / (3/4)</gadget>
<output>16</output>

<result>16</result>