Xiaohua went to the department store and bought two items. When paying, he left out the zero in the unit price of one of the items, and was going to pay 37 yuan to pick up the items. The salesperson said that you misunderstood the payment of 91 yuan. How much is the unit price of the wrong item?
小华到百货商城买了两件商品，在付款时，他把其中一件商品单价个位上的零漏掉了，准备付37元取货．售货员说你看错了应付款91元．看错的商品单价是多少元？
<gadget id="calculator">91 - 37</gadget>
<output>54</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">54 / 9</gadget>
<output>6</output>

<gadget id="calculator">6 * 10</gadget>
<output>60</output>

<result>60</result>