Xiao Ming and three classmates go to the zoo together. The children’s fare in the zoo is 30 yuan per person, so how much money should they bring at least?
小明与三位同学一起去动物园，动物园儿童票价为每人30元，那么他们至少要带多少钱才够？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">30 * 4</gadget>
<output>120</output>

<result>120</result>