The package tickets for the Science and Technology Palace used to be 30 yuan each, and the discount was 20% during the June 1st period. How much can you save by buying a set of such tickets?
科技宫的套票原来每套30元，六一期间八折优惠，购买一套这样的套票能省多少元？
<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)</gadget>
<output>6</output>

<result>6</result>