There is a ditch 15 meters long, 3 decimeters wide, and 1 decimeter deep beside the school playground. At least how many cubic decimeters of sand and soil must be transported to fill the ditch.
学校操场边有一条长15米，宽3分米，深1分米的水沟，至少要运来多少立方分米的沙土才能把水沟填平．
<gadget id="calculator">15 * 10</gadget>
<output>150</output>

<gadget id="calculator">150 * 3 * 1</gadget>
<output>450</output>

<result>450</result>