Wang Chao is going to spend 10 yuan to buy 4 exercise books and some ballpoint pens. If there is no exercise book, it costs 0.5 yuan, and each ballpoint pen is 1.6 yuan. How many ballpoint pens can Wang Chao buy at most? (column equation solution)
王超准备用10元钱买4本练习本和一些圆珠笔，没本练习本0.5元，每枝圆珠笔1.6元，王超最多可以买几枝圆珠笔？(列方程解答)
<gadget id="calculator">0.5 * 4</gadget>
<output>2</output>

<gadget id="calculator">10 - 2</gadget>
<output>8</output>

<gadget id="calculator">8 / 1.6</gadget>
<output>5</output>

<result>5</result>