When Xiaohong calculates 18*(□+3), it is 18*□+3, how much difference is it from the correct result
小红在计算18*(□+3)时，算成了18*□+3这样比正确结果相差多少
<gadget id="calculator">3 * 18</gadget>
<output>54</output>

<gadget id="calculator">54 - 3</gadget>
<output>51</output>

<result>51</result>