A bundle of wires is 500 meters long, first 215 meters were used up, and then 185 meters were used up, how many meters are left?
一捆电线长500米，先用去了215米，后来又用去了185米，还剩下多少米？
<gadget id="calculator">215 + 185</gadget>
<output>400</output>

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

<result>100</result>