Build a circular flower pond with bricks, with an outer diameter of 10 meters, an inner diameter of 8 meters, and a height of 1 meter. Each brick is 30 cm long, 15 cm wide, and 5 cm thick. How many bricks are needed to build this flower pond? (π takes 3.14)
用砖砌一个圆形花池，外直径10米，内直径8米，高1米，每块砖长30厘米，宽15厘米，厚5厘米，砌这个花池需要用多少块砖？(π取3.14)
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">25 - 16</gadget>
<output>9</output>

<gadget id="calculator">30 * 15 * 5</gadget>
<output>2_250</output>

<gadget id="calculator">1_000_000 / 2_250</gadget>
<output>4_000/9 = around 444.444444</output>

<gadget id="calculator">3.14 * 9 * 1 * (4_000/9)</gadget>
<output>12_560</output>

<result>12_560</result>