To pave a classroom, if you use square bricks with a side length of 3dm, a total of 800 pieces are needed. If you use square bricks with a side length of 4dm, how many pieces are needed? (Solve with ratio)
铺一间教室，如果用边长3dm的方砖，共需800块，如果改用边长为4dm的方砖，需要多少块？(用比例解)
<gadget id="calculator">3 * 3 * 800</gadget>
<output>7_200</output>

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

<gadget id="calculator">7_200 / 16</gadget>
<output>450</output>

<result>450</result>