"Six-" in Fat Donglai Mall is holding an activity. The unit price of a pen is 6 yuan, and students buy 5 pens and get 1 free. Xiao Ming bought 5 at a time, how much is each cheaper than usual?
胖东来商场"六-"搞活动，一种钢笔单价6元，学生买5支送1支．小明一次买了5支，每支比平时便宜多少元？
<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">6 * (5/6)</gadget>
<output>5</output>

<gadget id="calculator">6 - 5</gadget>
<output>1</output>

<result>1</result>