It takes 4,000 pieces to pave the floor with square bricks with a side length of 15 cm. If the floor is paved with square bricks with a side length of 25 cm, how many pieces are needed? (Answer with proportional knowledge)
用边长15厘米的方砖铺地，需要4000块，如果改用边长为25厘米的方砖铺地，那么需要多少块？(用比例知识解答)
<gadget id="calculator">15 * 15 * 4_000</gadget>
<output>900_000</output>

<gadget id="calculator">25 * 25</gadget>
<output>625</output>

<gadget id="calculator">900_000 / 625</gadget>
<output>1_440</output>

<result>1_440</result>