Xiaohui goes to the zoo with her father, mother, grandpa, and grandma. The ticket price is: 8.5 yuan per ticket for adults and 4.5 yuan per ticket for children. How much does it cost to buy tickets?
小慧和爸爸、妈妈、爷爷、奶奶去动物园，门票票价为：成人每张8.5元，儿童每张4.5元．买门票一共要花多少钱？
<gadget id="calculator">8.5 * 4</gadget>
<output>34</output>

<gadget id="calculator">34 + 4.5</gadget>
<output>38.5</output>

<result>38.5</result>