It takes 2,000 bricks to pave the classroom with square bricks with a side length of 15 cm; how many bricks are needed to pave the floor with square bricks with a side length of 25 cm? (Solution with proportional knowledge)
用边长是15厘米的方砖给教室铺地，需要2000块；如果改用边长25厘米的方砖铺地，需要多少块砖？(用比例知识解)
<gadget id="calculator">15 * 15 * 2_000</gadget>
<output>450_000</output>

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

<gadget id="calculator">450_000 / 625</gadget>
<output>720</output>

<result>720</result>