Xiaoming’s family wants to lay floor tiles for the living room, and it takes 900 pieces to pave with square bricks with a side length of 20 cm. If they use square bricks with a side length of 30 cm, how many pieces are needed?
小明家要给客厅铺地砖，用边长20厘米的正方形方砖铺需要900块，如果改用边长为30厘米的方砖铺，需要多少块？
<gadget id="calculator">20 * 20 * 900</gadget>
<output>360_000</output>

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

<gadget id="calculator">360_000 / 900</gadget>
<output>400</output>

<result>400</result>