The little sloppy was doing a calculation problem, and he lost sight of the parentheses in 3*﹙□+20﹑, so the result he got was different from the correct answer.
小马虎在做计算题，他把3*﹙□+20﹚中的括号看丢了，这样他得到的结果与正确答案相差多少．
<gadget id="calculator">60 - 20</gadget>
<output>40</output>

<result>40</result>