The three members of Fangfang’s family travel by train. The one-way train fare for children is 26.7 yuan, and the one-way adult fare is twice the price for children. How much is the round-trip transportation fee for Fangfang’s family?
芳芳一家三口乘火车出去旅游，火车单程儿童票价26.7元，单程成人票价是儿童票价的2倍，芳芳一家旅游往返的交通费是多少钱？
<gadget id="calculator">26.7 * 2 * 2</gadget>
<output>106.8</output>

<gadget id="calculator">106.8 + 26.7</gadget>
<output>133.5</output>

<gadget id="calculator">133.5 * 2</gadget>
<output>267</output>

<result>267</result>