Only two cakes can be baked at a time, and both sides must be baked for 2 minutes on each side. How many minutes does it take to bake 7 cakes?
每次只能烙两张饼，两面都要烙，每面2分钟．烙7张饼要多少分钟．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 * 2 * 2</gadget>
<output>8</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<gadget id="calculator">8 + 6</gadget>
<output>14</output>

<result>14</result>