There is a four-digit number, add a decimal point after one of its digits, and add it to the original number to get 1357.4. What is the four-digit number?
有一个四位数，在它的某位数字后加上一个小数点，再与原数相加得1357.4，这个四位数是多少？
<gadget id="calculator">0.1 + 1</gadget>
<output>1.1</output>

<gadget id="calculator">1_357.4 / 1.1</gadget>
<output>1_234</output>

<result>1_234</result>