A classroom needs 320 square bricks with a side length of 0.5 meters to pave the floor. If the square bricks with a side length of 0.3 meters are used instead, how many square bricks are needed? (Solve with ratio)
一间教室，用边长为0.5米的方砖铺地，需要320块，如果改用边长增加0.3米的方砖铺地，需要多少块方砖？(用比例解)
<gadget id="calculator">0.5 * 0.5 * 320</gadget>
<output>80</output>

<gadget id="calculator">0.5 * 0.3</gadget>
<output>0.15</output>

<gadget id="calculator">0.5 * 0.5</gadget>
<output>0.25</output>

<gadget id="calculator">0.3 * 0.3</gadget>
<output>0.09</output>

<gadget id="calculator">0.3 * 0.5</gadget>
<output>0.15</output>

<gadget id="calculator">0.15 + 0.25 + 0.09 + 0.15</gadget>
<output>0.64</output>

<gadget id="calculator">80 / 0.64</gadget>
<output>125</output>

<result>125</result>