There is a swimming pool in Hope Elementary School, which is 30m long, 18m wide, and 1.5m deep. A layer of cement needs to be applied on all surfaces of the swimming pool. If 5kg of cement is used per square meter, how many kilograms of cement is needed at least?
希望小学有一个游泳池，长30m，宽18m，深1.5m，要在游泳池的各个面上抹一层水泥，如果每平方米用水泥5千克，至少需要水泥多少千克？
<gadget id="calculator">30 * 18</gadget>
<output>540</output>

<gadget id="calculator">30 * 1.5</gadget>
<output>45</output>

<gadget id="calculator">18 * 1.5</gadget>
<output>27</output>

<gadget id="calculator">540 + 45 + 27</gadget>
<output>612</output>

<gadget id="calculator">612 * 2</gadget>
<output>1_224</output>

<gadget id="calculator">1_224 - 540</gadget>
<output>684</output>

<gadget id="calculator">684 * 5</gadget>
<output>3_420</output>

<result>3_420</result>