There are 10 books on the table. Two-fifths of them are reading books and three-tenths of them are math books. There is one fewer science book than math books and the rest are history books. How many history books are there?
Out of the 10 books, 10 x 2/5 = 
<gadget id="calculator">10*2/5</gadget>
<output>4</output>
4 are reading books.
While 10 x 3/10 = 
<gadget id="calculator">10*3/10</gadget>
<output>3</output>
3 are math books.
There are 3 - 1 = 
<gadget id="calculator">3-1</gadget>
<output>2</output>
2 science books.
So, the total number of reading, math, and science books is 4 + 3 + 2 = 
<gadget id="calculator">4+3+2</gadget>
<output>9</output>
9.
Thus, there is only 10 - 9 = 
<gadget id="calculator">10-9</gadget>
<output>1</output>
1 history book.

<result>1</result>