The original price of each arithmetic book is 3 yuan, and the current price is 5 yuan for 10 copies. How much is the current price of each arithmetic book cheaper than the original price.
算术本原价每本3元，现价5元10本，每本算术本现价比原价便宜多少元．
<gadget id="calculator">10 / 5</gadget>
<output>2</output>

<gadget id="calculator">3 - 2</gadget>
<output>1</output>

<result>1</result>