A set of 4 "Encyclopedia" was originally priced at 23.2 yuan, but each set was only sold at 17.4 yuan during the Children's Day promotion. How much is each original copy more expensive than the promotional copy?
4本一套的《百科全书》原来售价23.2元，六一儿童节促销每套只卖17.4元．原来每本比促销每本贵多少钱？
<gadget id="calculator">23.2 - 17.4</gadget>
<output>5.8</output>

<gadget id="calculator">5.8 / 4</gadget>
<output>1.45</output>

<result>1.45</result>