The engineering team laid a 1,500-meter-long highway for 4 days, and 150 meters were laid every day. The remaining 180 meters are laid every day, how many days will it take to complete the laying?
工程队铺设一条长1500米的公路，已铺设了4天，每天铺设150米．余下的每天铺设180米，还要几天铺设完成？
<gadget id="calculator">150 * 4</gadget>
<output>600</output>

<gadget id="calculator">1_500 - 600</gadget>
<output>900</output>

<gadget id="calculator">900 / 180</gadget>
<output>5</output>

<result>5</result>