Xiaohong goes to the amusement park with her father and mother. The one-way fare is 21.5 yuan per person, and the children's ticket is half price. How much is the round-trip transportation fee?
小红和爸爸、妈妈去游乐园，单程票价每人21.5元，儿童票半价，往返交通费需要多少钱？
<gadget id="calculator">21.5 * 2</gadget>
<output>43</output>

<gadget id="calculator">21.5 / 2</gadget>
<output>10.75</output>

<gadget id="calculator">43 + 10.75</gadget>
<output>53.75</output>

<gadget id="calculator">53.75 * 2</gadget>
<output>107.5</output>

<result>107.5</result>