A house needs to be paved with square bricks. If you use square floor tiles with a side length of 0.3 meters, a total of 400 pieces are needed; if you use square floor tiles with a side length of 0.5 meters, how many pieces are needed in total?
一间房子要用方砖铺地，如果用边长0.3米的正方形地砖，一共需要400块；如果改用边长0.5米的正方形地砖，一共需要多少块？
<gadget id="calculator">0.5 * 0.5</gadget>
<output>0.25</output>

<gadget id="calculator">400 / 0.25</gadget>
<output>1_600</output>

<gadget id="calculator">0.3 * 0.3 * 1_600</gadget>
<output>144</output>

<result>144</result>