Teacher Zhang at the school bought prizes for his classmates. He bought 5 diaries at 4.6 yuan each; he bought 5 pens and gave the salesperson 100 yuan, and got back 44.5 yuan. What is the unit price of each pen?
学校张老师为班上同学购买奖品，买了5本日记本，每本4.6元；买了5枝钢笔，给售货员100元钱，找回了44.5元钱．每枝钢笔的单价是多少？
<gadget id="calculator">4.6 * 5</gadget>
<output>23</output>

<gadget id="calculator">100 - 44.5 - 23</gadget>
<output>32.5</output>

<gadget id="calculator">32.5 / 5</gadget>
<output>6.5</output>

<result>6.5</result>