It takes 200 pieces to pave a piece of ground with floor tiles with a side length of 30 cm. If the floor tiles with a side length of 60 cm are used instead, how many such floor tiles are needed? (Solution with proportional knowledge)
铺一块地面，用边长是30厘米的地砖铺，需要200块，如果改用边长是60厘米的地砖铺，需要多少块这样的地砖？(用比例知识解)
<gadget id="calculator">30 * 30 * 200</gadget>
<output>180_000</output>

<gadget id="calculator">60 * 60</gadget>
<output>3_600</output>

<gadget id="calculator">180_000 / 3_600</gadget>
<output>50</output>

<result>50</result>