The road from city A to city B is 360 kilometers long. A car travels at 90 km/h on a highway and at 60 km/h on an ordinary road. How much time is saved by taking the expressway from city A to city B compared with ordinary roads?
从甲城到乙城的公路长360千米．一辆汽车走高速路的速度是90千米/时，走普通公路的速度是60千米/时．从甲城去乙城走高速路比普通公路节省多少时间？
<gadget id="calculator">360 / 60</gadget>
<output>6</output>

<gadget id="calculator">360 / 90</gadget>
<output>4</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<result>2</result>