A dictionary is 40 mm thick, and a math book is 5 mm thick. How many math books are stacked exactly as thick as a dictionary?
字典厚40毫米，数学书厚5毫米，几本数学书叠起来正好和一本字典一样厚？
<gadget id="calculator">40 / 5</gadget>
<output>8</output>

<result>8</result>