The school builds a new student swimming pool with a length of 50m, a width of 30m and a depth of 1.4m. Now it is necessary to smear cement around the pool and the bottom surface. If 3kg of cement is used per square meter, how many tons of cement are needed in total?
学校新建一个长50m，宽30m，深1.4m的学生游泳池．现在要在池的四周和底面抹上水泥，如果每平方米用水泥3kg，共需水泥多少吨？
<gadget id="calculator">50 * 30</gadget>
<output>1_500</output>

<gadget id="calculator">50 * 1.4</gadget>
<output>70</output>

<gadget id="calculator">30 * 1.4</gadget>
<output>42</output>

<gadget id="calculator">70 + 42</gadget>
<output>112</output>

<gadget id="calculator">112 * 2</gadget>
<output>224</output>

<gadget id="calculator">1_500 + 224</gadget>
<output>1_724</output>

<gadget id="calculator">3 / 1_000</gadget>
<output>3/1_000 = around 0.003</output>

<gadget id="calculator">1_724 * (3/1_000)</gadget>
<output>1_293/250 = around 5.172</output>

<result>1_293/250 = around 5.172</result>