Xiaoming's mother uses a pan to make pancakes, put up to 3 pancakes in the pan at a time, and it takes 4 minutes to bake a pancake (2 minutes each for front and back). Mom has baked 7 cakes in total, how many minutes will it take at least?
小明妈妈用平底锅烙饼，锅中每次最多放3只饼，烙一只饼要4分钟(正、反各2分钟)．妈妈一共烙了7只饼，至少要用几分钟？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<result>10</result>