The school plans to renovate the teaching building. The teaching building has 4 floors, and each floor has 5 classrooms. If each classroom is equipped with 6 lights, how many lights will be installed in this teaching building?
学校准备对教学楼进行装修，教学楼一共有4层，每层有5个教室，如果每个教室装6盏灯，这幢教学楼里一共要装多少盏灯？
<gadget id="calculator">6 * 5 * 4</gadget>
<output>120</output>

<result>120</result>