Xiaofang and her father go up the stairs. When her father reaches the 4th floor, Xiaofang goes to the 2nd floor. When her father reaches the 10th floor, how many floors does Xiaofang go to?
小芳和爸爸上楼梯，当爸爸走到4楼时，小芳走到2楼，那么当爸爸走到10楼时，小芳走到了几楼？
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<gadget id="calculator">9 / 3 / 1</gadget>
<output>3</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<result>4</result>