If you look at my house number upside down, it is a four-digit number, which is 7875 larger than the original number. What is my house number?
将我家门牌号码倒置着看是一个四位数，它比原来的号码大7875，我家门牌号码是多少．
<gadget id="calculator">9_861 - 7_875</gadget>
<output>1_986</output>

<result>1_986</result>