If you use square bricks to pave the floor of a classroom, if you use square bricks with a side length of 80 cm, you need 100 pieces. If you use square bricks with a side length of 50 cm instead, how many pieces are needed? (answer with ratio)
用方砖铺一间教室的地面，如果用边长80厘米的方砖要100块，如果改用边长50厘米的方砖来铺，需要多少块？(用比例解答)
<gadget id="calculator">80 * 80 * 100</gadget>
<output>640_000</output>

<gadget id="calculator">50 * 50</gadget>
<output>2_500</output>

<gadget id="calculator">640_000 / 2_500</gadget>
<output>256</output>

<result>256</result>