A certain place needs to pay at least 0.8 yuan for each call (within 3 minutes, including 3 minutes). If it exceeds 3 minutes, an additional 0.3 yuan will be paid for every 1 minute exceeded. Junjun made a phone call and paid 2.9 yuan. How many minutes did he make?
某地打电话每次至少要缴费0.8元(3分钟内，含3分钟)．如果超过3分钟，每超过1分钟再交0.3元．军军打一次电话，缴费2.9元，他打了几分钟的电话？
<gadget id="calculator">2.9 - 0.8</gadget>
<output>2.1</output>

<gadget id="calculator">2.1 / 0.3</gadget>
<output>7</output>

<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<result>10</result>