A pool is 20 meters long, 5 meters wide, and 2 meters deep. How many pieces of square tiles with a side length of 1 decimeter are built on the sides and bottom of the pool?
一水池长20米，宽5米，深2米，在这个水池的四周和底面砌上边长为1分米的正方形瓷砖，共需多少块？
<gadget id="calculator">20 * 5</gadget>
<output>100</output>

<gadget id="calculator">20 * 2 * 2</gadget>
<output>80</output>

<gadget id="calculator">5 * 2 * 2</gadget>
<output>20</output>

<gadget id="calculator">100 + 80 + 20</gadget>
<output>200</output>

<gadget id="calculator">1 / 100</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">1 * (1/100)</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">200 / (1/100)</gadget>
<output>20_000</output>

<result>20_000</result>