A shopping mall held a promotional activity and sold some products at a discount. My mother bought a piece of clothing for 240 yuan in the mall, which was 60 yuan cheaper than the original price. How much discount is this dress on sale for?
某商场进行促销活动，对一些商品打折出售，妈妈在商场花了240元买了一件衣服，比原价便宜了60元．这件衣服是打几折出售的？
<gadget id="calculator">240 + 60</gadget>
<output>300</output>

<gadget id="calculator">240 / 300</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>