supermarket offers discounts to customers, stipulating: 10% discount for one-time shopping of 50 yuan or more; 20% discount for more than 200 yuan. Uncle Li paid 30 yuan for the first time, and 162 yuan for the second time. If he buys the same product at one time, how much less can he pay?
某超市对顾客实行优惠，规定：一次性购物满50元，打九折；超过200元，超过部分打八折．李叔叔第一次付款30元，第二次付款162元，如果他一次性购买同样的商品，可以少付多少元？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">162 / (9/10)</gadget>
<output>180</output>

<gadget id="calculator">180 + 30</gadget>
<output>210</output>

<gadget id="calculator">210 * (9/10)</gadget>
<output>189</output>

<gadget id="calculator">162 - 189</gadget>
<output>-27</output>

<gadget id="calculator">30 + (-27)</gadget>
<output>3</output>

<result>3</result>