To pave the floor with square bricks with a side length of 15 cm, 2000 pieces are needed. If the floor is paved with square bricks with a side length of 30 cm, how many bricks are needed?
用边长为15厘米的方砖铺地，需要2000块．如果改用边长30厘米的方砖铺地，需要多少块．
<gadget id="calculator">15 * 15 * 2_000</gadget>
<output>450_000</output>

<gadget id="calculator">30 * 30</gadget>
<output>900</output>

<gadget id="calculator">450_000 / 900</gadget>
<output>500</output>

<result>500</result>