Last year, Ganhaizi School purchased 108 math tools for the third to sixth grades. This year, the fourth grade department took out 12 pieces and donated them to Hand in Hand School. How many math tools do the fourth grade department have from last year? (column comprehensive formula calculation)
干海资学校去年购买了108件数学用具平均分到三至六年级，今年四年级部从中拿出了12件赠送给了手拉手学校，四年级部还有多少件去年分来的数学用具？(列综合算式计算)
<gadget id="calculator">108 / 4</gadget>
<output>27</output>

<gadget id="calculator">27 - 12</gadget>
<output>15</output>

<result>15</result>