To lay floor tiles for a conference room, 100 floor tiles with an area of 36 square decimeters are exactly covered. If you use floor tiles with a side length of 4 decimeters, how many pieces are needed at least?
给一间会议室铺地砖，用面积36平方分米的地砖100块正好铺满．如果改用边长4分米的地砖，至少需要多少块？
<gadget id="calculator">36 * 100</gadget>
<output>3_600</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">3_600 / 16</gadget>
<output>225</output>

<result>225</result>