Students have to plant 67 small flags (both ends) on the side of the school runway. The distance between each two small flags is 6 meters. How long is the school runway in meters?
同学们要在学校跑道一旁插67面小旗(两端都插)，每两面小旗间隔6米，学校跑道长多少米．
<gadget id="calculator">67 - 1</gadget>
<output>66</output>

<gadget id="calculator">6 * 66</gadget>
<output>396</output>

<result>396</result>