A 4,500-meter-long road is built, and 156 meters are built every day. It has been repaired for 25 days. How many meters are left to be repaired?
修一条长4500米的路，每天修156米，已经修了25天，还剩下多少米没有修？
<gadget id="calculator">156 * 25</gadget>
<output>3_900</output>

<gadget id="calculator">4_500 - 3_900</gadget>
<output>600</output>

<result>600</result>