Xiaofang's room is 4.5 meters long and 4 meters wide. How many square bricks with a side length of 0.5 meters are needed to pave the floor?
小芳的房间长4.5米，宽4米．用边长0.5米的方砖铺地，需要多少块？
<gadget id="calculator">0.5 * 0.5</gadget>
<output>0.25</output>

<gadget id="calculator">4 / 0.25</gadget>
<output>16</output>

<gadget id="calculator">4.5 * 16</gadget>
<output>72</output>

<result>72</result>