A calculator is 24 yuan, buy 4 get 1 free, Mr. Li bought 4 calculators at a time, how much is each cheaper?
一个计算器24元，买4个送1个，李老师一次买了4个计算器，每个便宜多少钱？
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">24 * (4/5)</gadget>
<output>96/5 = around 19.2</output>

<gadget id="calculator">24 - (96/5)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>