Uncle workers build a road, 6 meters a day, after 4 days, there are 40 meters left, how long is this road?
工人叔叔修一条公路，每天修6米，修了4天后，还剩40米，这条公路长多少米？
<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">24 + 40</gadget>
<output>64</output>

<result>64</result>