From 1 to 1000, how many times does the number 0 appear?
从1写到1000，数字0共出现过多少次．
<gadget id="calculator">20 * 8</gadget>
<output>160</output>

<gadget id="calculator">1 + 10 + 160 + 21</gadget>
<output>192</output>

<result>192</result>