The school teaching building has 3 floors, with 4 classrooms on each floor. If each classroom needs 12 fluorescent tubes, how many fluorescent tubes does this teaching building need at least?
学校教学楼有3层，每层4个教室．如果每个教室需12支日光灯管，这幢教学楼至少需多少支灯管？
<gadget id="calculator">4 * 3 * 12</gadget>
<output>144</output>

<result>144</result>