Xiaogang and his family traveled 357 kilometers by car to a certain place. If the fuel consumption per 100 kilometers was 7 liters, at least how many liters of gasoline should be prepared to ensure that there is no refueling on the way back and forth?
小刚全家自驾车到某地旅游，全程357千米，如果每行驶100千米耗油7升，至少要准备多少升汽油才能保证往返中途不再加油？
<gadget id="calculator">2 / 100</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">357 * (1/50) * 7</gadget>
<output>2_499/50 = around 49.98</output>

<result>2_499/50 = around 49.98</result>