What is the difference (9/10) between the largest three-digit number and the smallest four-digit number.
最大的三位数与最小的四位数的差的(9/10)是多少．
<gadget id="calculator">1_000 - 999</gadget>
<output>1</output>

<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 * (9/10)</gadget>
<output>9/10 = around 0.9</output>

<result>9/10 = around 0.9</result>