Due to carelessness, the little sloppy miscalculated 20*(□+3) as 20*□+3. Please help me to calculate. How much is the difference between the result he got and the correct result?
小马虎由于粗心大意，把20*(□+3)错算成20*□+3，请你帮忙算一算，他得到的结果与正确结果相差多少？
<gadget id="calculator">20 * 3</gadget>
<output>60</output>

<gadget id="calculator">60 - 3</gadget>
<output>57</output>

<result>57</result>