The school cafeteria is paved with square granite slabs with a side length of 3 decimeters, which costs 640 yuan. If you use square granite slabs with a side length of 4 decimeters instead, how many pieces are needed? (Solve with ratio)
学校食堂用边长为3分米的正方形花岗岩板材铺地，需要640块．若改用边长为4分米的正方形花岗岩板材铺地，需要多少块？(用比例解)
<gadget id="calculator">3 * 3 * 640</gadget>
<output>5_760</output>

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

<gadget id="calculator">5_760 / 16</gadget>
<output>360</output>

<result>360</result>