Home appliance shopping mall promotion, 10% off sales. How much can you save by buying a TV with an original price of 6,400 yuan?
家电商场促销，打九折销售．买一台原价6400元的电视机，能节省多少元？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 - (9/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">6_400 * (1/10)</gadget>
<output>640</output>

<result>640</result>