The original price of a set of clothes is 400 yuan, but now it is sold at a 30% discount. How much is the buyer’s discount?
一套衣服原价400元，现在打7折出售，购者便宜了多少元？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">400 * (3/10)</gadget>
<output>120</output>

<result>120</result>