Tickets for the children's playground used to be 30 yuan each, and the discount was 20% during the "Spring Festival". Teacher Liu's family of 3 went to the playground to play. How much yuan can I save by buying tickets?
儿童游乐场的门票原来每张30元，"春节"期间八折优惠，刘老师一家3口去游乐场玩，购买门票一共能省多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 * (1/5) * 3</gadget>
<output>18</output>

<result>18</result>