It takes 2,500 pieces to pave the classroom 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? (Solve using ratio method)
用边长15厘米的方砖给教室铺地，需要2500块；如果改用边长为25厘米的方砖铺地，那么需要多少块？(用比例的方法解答)
<gadget id="calculator">15 * 15 * 2_500</gadget>
<output>562_500</output>

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

<gadget id="calculator">562_500 / 625</gadget>
<output>900</output>

<result>900</result>