A rectangular classroom uses square bricks with a side length of 3 decimeters, and 480 bricks are exactly covered. If you use square bricks with a side length of 4 decimeters instead, how many pieces are needed?
一间长方形教室用边长3分米的方砖，480块正好铺满．如果改用边长4分米的方砖，需要多少块？
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">480 / 16</gadget>
<output>30</output>

<gadget id="calculator">3 * 3 * 30</gadget>
<output>270</output>

<result>270</result>