The school conference room is paved with square bricks. It takes 500 pieces to use a side length of 4dm; if it is replaced by square bricks with a side length of 5dm, how many pieces are needed? (Solve with ratio)
学校会议室用方砖铺地．用边长4dm的需要500块；如果改用边长5dm的方砖铺，需要多少块？(用比例解)
<gadget id="calculator">4 * 4 * 500</gadget>
<output>8_000</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">8_000 / 25</gadget>
<output>320</output>

<result>320</result>