It takes 6 minutes to weld 4 iron bars into a straight bar. According to this calculation, if 8 such iron bars are welded into a straight bar, how many minutes will it take in total.
把4根铁条焊接成一根直条，用去6分钟，照这样计算，如果把8根这样的铁条焊接成一根直条，一共需要多少分钟．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">2 * 7</gadget>
<output>14</output>

<result>14</result>