Type A stamps have a face value of (4/5) yuan, and Type B stamps have a face value of (1/10) yuan. If you buy 20 stamps of each of the two types, how much more will you pay for Type A stamps than Type B stamps?
甲种邮票面值(4/5)元，乙种邮票面值(1/10)元．两种邮票各买20张，买甲种邮票比买乙种邮票多付多少元钱？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">20 * (4/5)</gadget>
<output>16</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">20 * (1/10)</gadget>
<output>2</output>

<gadget id="calculator">16 - 2</gadget>
<output>14</output>

<result>14</result>