Using "ten thousand" as the unit, the maximum difference between the exact number of 400,000 and the approximate number of 400,000 is the maximum.
用"万"作单位，准确数40万和近似数40万作比较最多相差多少．
<gadget id="calculator">40 * 10_000</gadget>
<output>400_000</output>

<gadget id="calculator">400_000 - 395_000</gadget>
<output>5_000</output>

<result>5_000</result>