Hongqi Primary School dug a cuboid bunker with a length of 5m, a width of 3m and a depth of 0.5m on the playground. If the sand weighs 1.8 tons per cubic meter, how many tons of sand are needed to fill the bunker?
红旗小学在操场上挖了一个长5m，宽3m，深0.5m的长方体沙坑，如果每立方米沙重1.8吨，需要多少吨沙子才能填满这个沙坑？
<gadget id="calculator">5 * 3 * 0.5 * 1.8</gadget>
<output>13.5</output>

<result>13.5</result>