There are 28 classrooms in a four-story building, each classroom is equipped with 8 lamps, 128 lamps have been installed, how many lamps are still installed?
一座四层楼房有28个教室，每个教室装8盏灯，已经装好了128盏，还要装多少盏灯？
<gadget id="calculator">28 * 8</gadget>
<output>224</output>

<gadget id="calculator">224 - 128</gadget>
<output>96</output>

<result>96</result>