Hope primary school decoration multimedia classroom. It is planned to pave the floor with glazed square bricks with a side length of 30 cm, and it needs 900 pieces. How many pieces are actually needed for paving the floor with square marble with a side length of 50 cm? (Answer with proportional knowledge)
希望小学装修多媒体教室．计划用边长30厘米的釉面方砖铺地，需要900块，实际用边长50厘米的方大理石铺地，需要多少块？(用比例知识解答)
<gadget id="calculator">30 * 30 * 900</gadget>
<output>810_000</output>

<gadget id="calculator">50 * 50</gadget>
<output>2_500</output>

<gadget id="calculator">810_000 / 2_500</gadget>
<output>324</output>

<result>324</result>