If the bottom of a swimming pool is paved with square bricks with a side length of 5 decimeters, 480 pieces are needed. If it is replaced with square bricks with a side length of 4 decimeters, how many pieces are needed? (Solution with proportional knowledge)
一个游泳池的池底用边长是5分米的方砖铺，需480块，如果改用边长是4分米的方砖，需要多少块？(用比例知识解)
<gadget id="calculator">5 * 5 * 480</gadget>
<output>12_000</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">12_000 / 16</gadget>
<output>750</output>

<result>750</result>