- A two-digit number, after being reduced by 10 times, the difference with the original number is 81, what is the two-digit number?
-个两位数，缩小10倍后与原数差为81，这个两位数是多少．
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">81 / 9</gadget>
<output>9</output>

<gadget id="calculator">9 * 10</gadget>
<output>90</output>

<result>90</result>