In order to build a conservation-oriented society and strengthen citizens' awareness of water conservation, a certain city has established the following water charging standards: when the monthly water consumption of each household does not exceed 10 tons, the water fee per ton is 1.8 yuan; if it exceeds 10 tons, the excess is charged per ton Water, the water fee will be increased by 50% on the basis of 1.8 yuan per ton. Uncle Wang’s family used 18 tons of water last month. How much is the water bill?
为构建节约型社会，加强公民节水意识，某城市制定了以下用水收费标准：每户每月用水量不超过10吨时，每吨水费为1.8元；如果超过10吨，超出部分每吨水，水费在每吨1.8元的基础上要加价50%．王大伯家上个月用水18吨，需交水费多少元？
<gadget id="calculator">1.8 * 10</gadget>
<output>18</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1.8 * (1/2)</gadget>
<output>0.9</output>

<gadget id="calculator">1.8 + 0.9</gadget>
<output>2.7</output>

<gadget id="calculator">18 - 10</gadget>
<output>8</output>

<gadget id="calculator">2.7 * 8</gadget>
<output>21.6</output>

<gadget id="calculator">18 + 21.6</gadget>
<output>39.6</output>

<result>39.6</result>