The worker uncle wants to build a 30-kilometer-long road, and he builds 5 kilometers a day. After 5 days of repairing, how many kilometers are left to be repaired?
工人叔叔要修一条30千米长的公路，每天修5千米，修了5天，还有多少千米没有修？
<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">30 - 25</gadget>
<output>5</output>

<result>5</result>