The maximum speed of the EMU is 252 km/h, while the maximum speed of the ordinary train is 122 km/h. If the two trains run at the highest speed for 4 hours at the same time, how many kilometers will the EMU travel more than the ordinary train? (answer in two ways)
动车组的最高速度是252千米/时，而普通列车的最高速度是122千米/时．如果两车以最高速度同时运行4小时，动车组比普通列车多行驶多少千米？(用两种方法解答)
<gadget id="calculator">252 * 4</gadget>
<output>1_008</output>

<gadget id="calculator">122 * 4</gadget>
<output>488</output>

<gadget id="calculator">1_008 - 488</gadget>
<output>520</output>

<result>520</result>