The road team wants to build a 500-meter-long railway. On the first day, 168 meters were built, and on the second day, 232 meters were built. How many meters are left to be repaired? (in two ways)
公路队要修一条长500米的铁路，第一天修了168米，第二天修了232米，还剩多少米未修？(用两种方法)
<gadget id="calculator">168 + 232</gadget>
<output>400</output>

<gadget id="calculator">500 - 400</gadget>
<output>100</output>

<result>100</result>