swimming pool is 50 meters long, 30 meters wide and 3.5 meters deep. If square bricks with a side length of 2 decimeters are laid on the four walls and the bottom of the swimming pool, how many square bricks are needed in total?
一个游泳池长50米，宽30米，深3.5米．在游泳池的四壁和底部铺上边长2分米的方砖，共需方砖多少块？
<gadget id="calculator">50 * 30</gadget>
<output>1_500</output>

<gadget id="calculator">50 * 3.5</gadget>
<output>175</output>

<gadget id="calculator">30 * 3.5</gadget>
<output>105</output>

<gadget id="calculator">1_500 + 175 + 105</gadget>
<output>1_780</output>

<gadget id="calculator">1_780 * 2</gadget>
<output>3_560</output>

<gadget id="calculator">3_560 - 1_500</gadget>
<output>2_060</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) * (1/5)</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">2_060 / (1/25)</gadget>
<output>51_500</output>

<result>51_500</result>