The original price of electric fans is 280 yuan, and the current price is 190 yuan. The school bought 18 sets. How much cheaper can it be?
电风扇原价280元，现价190元，学校买了18台，能便宜多少钱？
<gadget id="calculator">280 - 190</gadget>
<output>90</output>

<gadget id="calculator">90 * 18</gadget>
<output>1_620</output>

<result>1_620</result>