There are 800 sheets of paper in a stack, and a piece of plastic is sandwiched between every 50 sheets of paper. How many pieces of plastic should be clipped in total?
一叠纸共800张，每50张纸之间夹一片塑料片，一共要夹多少片塑料片．
<gadget id="calculator">800 / 50</gadget>
<output>16</output>

<gadget id="calculator">16 - 1</gadget>
<output>15</output>

<result>15</result>