A villa with an area of 5400 square meters is paved with square bricks with a side length of 600 mm, and now it is paved with square bricks with a side length of 30 mm. How many square bricks should be used at this time?
5400平方米的別墅，用边长600mm的方砖铺地，现在又改用边长为30mm的方砖铺地，此时要用几块方砖？
<gadget id="calculator">5_400 / 0.0009</gadget>
<output>6_000_000</output>

<result>6_000_000</result>