Mom asked Xiaohong to go to the store to buy 5 pencils and 8 exercise books, and gave Xiaohong 3.8 yuan according to the price. As a result, Xiaohong bought 8 pencils and 5 exercise books, and got back 0.45 yuan. How much is a pencil?
妈妈让小红去商店买5支铅笔和8个练习本，按价钱给小红3.8元钱．结果小红却买了8支铅笔和5本练习本，找回0.45元．求一支铅笔多少元？
<gadget id="calculator">8 - 5</gadget>
<output>3</output>

<gadget id="calculator">0.45 / 3</gadget>
<output>0.15</output>

<gadget id="calculator">0.15 * 8</gadget>
<output>1.2</output>

<gadget id="calculator">3.8 - 1.2</gadget>
<output>2.6</output>

<gadget id="calculator">5 + 8</gadget>
<output>13</output>

<gadget id="calculator">2.6 / 13</gadget>
<output>0.2</output>

<result>0.2</result>