Wisdom Bookstore shipped back 480 copies of "Mathematical Stories", 20 copies per pack, and the returned "Thinking Training" was 8 packs less than "Mathematical Stories", how many packs of "Thinking Training" were shipped back?
智慧书店运回《数学故事》480本，每包20本，运回的《思维训练》比《数学故事》少8包，运回《思维训练》多少包？
<gadget id="calculator">480 / 20</gadget>
<output>24</output>

<gadget id="calculator">24 - 8</gadget>
<output>16</output>

<result>16</result>