The driver, Uncle Wang, fills up 30 liters of fuel at the gas station and goes to work at a company 180 kilometers away from the gas station. Calculated by the fact that each liter of gasoline can drive 8 kilometers, how many liters of fuel do you need to return?
司机王叔叔在加油站加了30升油后，去距离加油站180千米的公司去办事，按每升汽油可行驶8千米计算，回来还需要加油多少升？
<gadget id="calculator">180 * 2</gadget>
<output>360</output>

<gadget id="calculator">30 * 8</gadget>
<output>240</output>

<gadget id="calculator">360 - 240</gadget>
<output>120</output>

<gadget id="calculator">120 / 8</gadget>
<output>15</output>

<result>15</result>