Lele Clothing Store is holding a promotion to welcome Children’s Day. A piece of clothing is 120 yuan after a 20% discount. How much is this piece of clothing cheaper?
乐乐服装店进行迎六一促销活动，一件衣服打八折后是120元，这件衣服便宜多少元？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">120 / (4/5)</gadget>
<output>150</output>

<gadget id="calculator">150 - 120</gadget>
<output>30</output>

<result>30</result>