Xiao Ming’s house needs 600 pieces of tiles with a side length of 20 cm to decorate the wall of the bathroom. If it is replaced with tiles with a length of 30 cm and a width of 20 cm, how many pieces are needed?
小明家装修卫生间墙壁，用边长20厘米的瓷砖铺，需要600块，如果改用长30厘米，宽20厘米的瓷砖铺，需要多少块．
<gadget id="calculator">20 * 20 * 600</gadget>
<output>240_000</output>

<gadget id="calculator">30 * 20</gadget>
<output>600</output>

<gadget id="calculator">240_000 / 600</gadget>
<output>400</output>

<result>400</result>