There is a flower bed, the height is 0.5 meters, and the bottom is a square with a side length of 1.4 meters. It is surrounded by bricks with a thickness of 0.3 meters and filled with soil in the middle. If a total of 0.196 cubic meters of soil is filled, what is the height of the soil in meters?
有一个花坛，高0.5米，底面是边长1.4米的正方形．四周用砖砌成的，厚度是0.3米，中间填满泥土．如果一共填了0.196立方米的泥土，那么泥土的高度是多少米？
<gadget id="calculator">0.3 * 2</gadget>
<output>0.6</output>

<gadget id="calculator">1.4 - 0.6</gadget>
<output>0.8</output>

<gadget id="calculator">0.8 * 0.8</gadget>
<output>0.64</output>

<gadget id="calculator">0.196 / 0.64</gadget>
<output>0.30625</output>

<result>0.30625</result>