After the 0 in the ones digit of a three-digit number is removed, the number is 756 less than the original number. What is the original three-digit number?
一个三位数个位上的0去掉以后，这个数比原来少756，原来的这个三位数是多少？
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">756 / 9</gadget>
<output>84</output>

<gadget id="calculator">84 * 10</gadget>
<output>840</output>

<result>840</result>