classroom needs 320 yuan to pave the floor with square bricks with a side length of 5 decimeters. If you use square bricks with a side length of 4 decimeters, how many pieces are needed? (answer with ratio)
一间教室，用边长5分米的方砖铺地，需要320块．如果用边长是4分米的方砖铺，需要多少块？(用比例解答)
<gadget id="calculator">5 * 5 * 320</gadget>
<output>8_000</output>

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

<gadget id="calculator">8_000 / 16</gadget>
<output>500</output>

<result>500</result>