In order to create a "provincial civilized city", the municipal government plans to lay 320,000 pieces of floor tiles on Xidi Heng Street. It has been laid for 4 days, and 20,000 pieces are laid every day. A thousand tiles?
市政府为了创建"省文明城市"，计划在西堤横街铺设320千块地砖，现已铺设了4天，每天铺了20千块，剩下的要求在6天内铺完，平均每天要铺多少千块地砖？
<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<gadget id="calculator">320 - 80</gadget>
<output>240</output>

<gadget id="calculator">240 / 6</gadget>
<output>40</output>

<result>40</result>