Among the natural numbers not greater than 1000, A is the sum of all numbers whose unit digit is 8, and B is the sum of all numbers whose unit digit is 3. What is the difference between A and B?
在不大于1000的自然数中，A为所有个位数字为8的数之和，B为所有个位数字为3的数之和．A与B的差是多少？
<gadget id="calculator">1_000 / 10</gadget>
<output>100</output>

<gadget id="calculator">8 - 3</gadget>
<output>5</output>

<gadget id="calculator">100 * 5</gadget>
<output>500</output>

<result>500</result>