A store celebrated a sale by offering "buy 5 get 1 free" on facial tissues. One kind of facial tissue is 24 yuan per set. Mama Wang bought 5 sets at a time. How much cheaper can each set be?
一家商店庆促销，对面巾纸搞"买5送1"的活动．一种面巾纸每组24元，王妈妈一次买了5组，每组可以便宜多少元？
<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">24 * (5/6)</gadget>
<output>20</output>

<gadget id="calculator">24 - 20</gadget>
<output>4</output>

<result>4</result>